In this episode, we discuss research coming out of Columbia University to better connect humans with robots by having them detect, process, and respond to facial expressions!

Podcast: Finally! A Humanoid Robot You Can Trust

Our muscles are nature’s perfect actuators — devices that turn energy into motion. For their size, muscle fibers are more powerful and precise than most synthetic actuators. They can even heal from damage and grow stronger with exercise.For these reasons, engineers are exploring ways to power robots with natural muscles. They’ve demonstrated a handful of “biohybrid” robots that use muscle-based actuators to power artificial skeletons that walk, swim, pump, and grip. But for every bot, there’s a very different build, and no general blueprint for how to get the most out of muscles for any given robot design.Now, MIT engineers have developed a spring-like device that could be used as a basic skeleton-like module for almost any muscle-bound bot. The new spring, or “flexure,” is designed to get the most work out of any attached muscle tissues. Like a leg press that’s fit with just the right amount of weight, the device maximizes the amount of movement that a muscle can naturally produce.The researchers found that when they fit a ring of muscle tissue onto the device, much like a rubber band stretched around two posts, the muscle pulled on the spring, reliably and repeatedly, and stretched it five times more, compared with other previous device designs.The team sees the flexure design as a new building block that can be combined with other flexures to build any configuration of artificial skeletons. Engineers can then fit the skeletons with muscle tissues to power their movements.“These flexures are like a skeleton that people can now use to turn muscle actuation into multiple degrees of freedom of motion in a very predictable way,” says Ritu Raman, the Brit and Alex d'Arbeloff Career Development Professor in Engineering Design at MIT. “We are giving roboticists a new set of rules to make powerful and precise muscle-powered robots that do interesting things.”Raman and her colleagues report the details of the new flexure design in a&nbsp;<a href="https://onlinelibrary.wiley.com/doi/full/10.1002/aisy.202300834" target="_blank">paper appearing today</a> in the journal&nbsp;Advanced Intelligent&nbsp;Systems. The study’s MIT co-authors include Naomi Lynch ’12, SM ’23; undergraduate Tara Sheehan; graduate students Nicolas Castro, Laura Rosado, and Brandon Rios; and professor of mechanical engineering Martin Culpepper.<h2>Muscle pull</h2>When left alone in a petri dish in favorable conditions, muscle tissue will contract on its own but in directions that are not entirely predictable or of much use.“If muscle is not attached to anything, it will move a lot, but with huge variability, where it’s just flailing around in liquid,” Raman says.To get a muscle to work like a mechanical actuator, engineers typically attach a band of muscle tissue between two small, flexible posts. As the muscle band naturally contracts, it can bend the posts and pull them together, producing some movement that would ideally power part of a robotic skeleton. But in these designs, muscles have produced limited movement, mainly because the tissues are so variable in how they contact the posts. Depending on where the muscles are placed on the posts, and how much of the muscle surface is touching the post, the muscles may succeed in pulling the posts together but at other times may wobble around in uncontrollable ways.Raman’s group looked to design a skeleton that focuses and maximizes a muscle’s contractions regardless of exactly where and how it is placed on a skeleton, to generate the most movement in a predictable, reliable way.“The question is: How do we design a skeleton that most efficiently uses the force the muscle&nbsp;is generating?” Raman says.The researchers first considered the multiple directions that a muscle can naturally move. They reasoned that if a muscle is to pull two posts together along a specific direction, the posts should be connected to a spring that only allows them to move in that direction when pulled.“We need a device that is very soft and flexible in one direction, and very stiff in all other directions, so that when a muscle contracts, all that force gets efficiently converted into motion in one direction,” Raman says.<h2>Soft flex</h2>As it turns out, Raman found many such devices in Professor Martin Culpepper’s lab. Culpepper’s group at MIT specializes in the design and fabrication of machine elements such as miniature actuators, bearings, and other mechanisms, that can be built into machines and systems to enable ultraprecise movement, measurement, and control, for a wide variety of applications. Among the group’s precision machined elements are flexures — spring-like devices, often made from parallel beams, that can flex and stretch with nanometer precision.“Depending on how thin and far apart the beams are, you can change how stiff the spring appears to be,” Raman says.She and Culpepper teamed up to design a flexure specifically tailored with a configuration and stiffness to enable muscle tissue to naturally contract and maximally stretch the spring. The team designed the device’s configuration and dimensions based on numerous calculations they carried out to relate a muscle’s natural forces with a flexure’s stiffness and degree of movement.The flexure they ultimately designed is 1/100 the stiffness of muscle tissue itself. The device resembles a miniature, accordion-like structure, the corners of which are pinned to an underlying base by a small post, which sits near a neighboring post that is fit directly onto the base. Raman then wrapped a band of muscle around the two corner posts (the team molded the bands from live muscle fibers that they grew from mouse cells), and measured how close the posts were pulled together as the muscle band contracted.The team found that the flexure’s configuration enabled the muscle band to contract mostly along the direction between the two posts. This focused contraction allowed the muscle to pull the posts much closer together — five times closer — compared with previous muscle actuator designs.“The flexure is a skeleton that we designed to be very soft and flexible in one direction, and very stiff in all other directions,” Raman says. “When the muscle contracts, all the force is converted into movement in that direction. It’s a huge magnification.”The team found they could use the device to precisely measure muscle performance and endurance. When they varied the frequency of muscle contractions (for instance, stimulating the bands to contract once versus four times per second), they observed that the muscles “grew tired” at higher frequencies, and didn’t generate as much pull.“Looking at how quickly our muscles get tired, and how we can exercise them to have high-endurance responses — this is what we can uncover with this platform,” Raman says.The researchers are now adapting and combining flexures to build precise, articulated, and reliable robots, powered by natural muscles.“An example of a robot we are trying to build in the future is a surgical robot that can perform minimally invasive procedures inside the body,” Raman says. “Technically, muscles can power robots of any size, but we are particularly excited in making small robots, as this is where biological actuators excel in terms of strength, efficiency, and adaptability.”

MIT engineers have developed a new spring (shown in Petri dish) that maximizes the work of natural muscles. When living muscle tissue is attached to posts at the corners of the device, the muscle’s contractions pull on the spring, forming an effective, natural actuator. The spring can serve as a “skeleton” for future muscle-powered robots. Image: Felice Frankel

New modular, spring-like devices maximize the work of live muscle fibers so they can be harnessed to power biohybrid bots.

Engineers design flexible "skeletons" for soft, muscle-powered robots

In this episode, we discuss a breakthrough from ETH Zurich to mimic natural foot signals to the brain using state of the art neuroprosthetics. 

Podcast: Neuroprosthetics: The Next Step Towards Limb Reconstruction

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/f153920a-aca0-4937-863a-2cc925d11434?dark=false" class="fr-draggable" data-gtm-yt-inspected-9="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>Columbia engineers build Emo, a silicon-clad robotic face that makes eye contact and uses two AI models to anticipate and replicate a person’s smile before the person actually smiles -- a major advance in robots predicting human facial expressions accurately, improving interactions, and building trust between humans and robots.<section id="isPasted">What would you do if you walked up to a robot with a human-like head and it smiled at you first? You’d likely smile back and perhaps feel the two of you were genuinely interacting. But how does a robot know how to do this? Or a better question, how does it know to get you to smile back?While we’re getting accustomed to robots that are adept at verbal communication, thanks in part to advancements in large language models like ChatGPT, their nonverbal communication skills, especially facial expressions, have lagged far behind. Designing a robot that can not only make a wide range of facial expressions but also know when to use them has been a daunting task.&nbsp;</section><section><h2>Tackling the challenge</h2>The <a href="http://engineering.columbia.edu/" rel="nofollow" target="_blank">Creative Machines Lab</a> at <a href="http://engineering.columbia.edu/" rel="nofollow" target="_blank">Columbia Engineering</a> has been working on this challenge for more than five years. In a new study published today in <a href="https://www.science.org/doi/10.1126/scirobotics.adi4724" rel="nofollow" target="_blank">Science Robotics</a>, the group unveils Emo, a robot that anticipates facial expressions and executes them simultaneously with a human. It has even learned to predict a forthcoming smile about 840 milliseconds before the person smiles, and to co-express the smile simultaneously with the person.The team, led by <a href="https://www.engineering.columbia.edu/faculty/hod-lipson" rel="nofollow" target="_blank">Hod Lipson</a>, a leading researcher in the fields of artificial intelligence (AI) and robotics, faced two challenges: how to mechanically design an expressively versatile robotic face which involves complex hardware and actuation mechanisms, and knowing which expression to generate so that they appear natural, timely, and genuine. The team proposed training a robot to anticipate future facial expressions in humans and execute them simultaneously with a person. The timing of these expressions was critical -- delayed facial mimicry looks disingenuous, but facial co-expression feels more genuine since it requires correctly inferring the human's emotional state for timely execution.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzExNTg1NTM0ODUxLXl1aGFuZy1odWEtb2YtY3JlYXRpdmUtbWFjaGluZXMtbGFiLWZhY2UtdG8tZmFjZS13aXRoLWVtby5wbmciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Yuhang Hu of Creative Machines Lab face-to-face with Emo. Image: Courtesy of Creative Machines Lab<h2 id="isPasted">How Emo connects with you</h2>Emo is a human-like head with a face that is equipped with 26 actuators that enable a broad range of nuanced facial expressions. The head is covered with a soft silicone skin with a magnetic attachment system, allowing for easy customization and quick maintenance. For more lifelike interactions, the researchers integrated high-resolution cameras within the pupil of each eye, enabling Emo to make eye contact, crucial for nonverbal communication.The team developed two AI models: one that predicts human facial expressions by analyzing subtle changes in the target face and another that generates motor commands using the corresponding facial expressions.To train the robot how to make facial expressions, the researchers put Emo in front of the camera and let it do random movements. After a few hours, the robot learned the relationship between their facial expressions and the motor commands -- much the way humans practice facial expressions by looking in the mirror. This is what the team calls “self modeling” – similar to our human ability to imagine what we look like when we make certain expressions.Then the team ran videos of human facial expressions for Emo to observe them frame by frame. After training, which lasts a few hours, Emo could predict people’s facial expressions by observing tiny changes in their faces as they begin to form an intent to smile.“I think predicting human facial expressions accurately is a revolution in HRI. Traditionally, robots have not been designed to consider humans' expressions during interactions. Now, the robot can integrate human facial expressions as feedback,” said the study’s lead author Yuhang Hu, who is a PhD student at Columbia Engineering in Lipson’s lab. “When a robot makes co-expressions with people in real-time, it not only improves the interaction quality but also helps in building trust between humans and robots. In the future, when interacting with a robot, it will observe and interpret your facial expressions, just like a real person.”<iframe width="640" height="360" src="https://www.youtube.com/embed/pWTTzR_wXuQ?&amp;wmode=opaque&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-9="true" id="556492795" title="Human-Robot Facial Co-expression">&nbsp;</iframe>Go inside the Creative Machines Lab to watch Emo's facial co-expression. Video Credit: Yuhang Hu, Columbia Engineering<h2 id="isPasted">What’s next</h2>The researchers are now working to integrate verbal communication, using a large language model like ChatGPT into Emo. As robots become more capable of behaving like humans, Lipson is well aware of the ethical considerations associated with this new technology.“Although this capability heralds a plethora of positive applications, ranging from home assistants to educational aids, it is incumbent upon developers and users to exercise prudence and ethical considerations,” says Lipson, James and Sally Scapa Professor of Innovation in the Department of <a href="https://www.me.columbia.edu/" rel="nofollow" target="_blank">Mechanical Engineering</a> at Columbia Engineering, co-director of the <a href="https://make.columbia.edu/" rel="nofollow" target="_blank">Makerspace</a> at Columbia, and a member of the <a href="https://datascience.columbia.edu/" rel="nofollow" target="_blank">Data Science Institute</a>. “But it’s also very exciting -- by advancing robots that can interpret and mimic human expressions accurately, we're moving closer to a future where robots can seamlessly integrate into our daily lives, offering companionship, assistance, and even empathy. Imagine a world where interacting with a robot feels as natural and comfortable as talking to a friend.”&nbsp;</section>

The study's lead author, Yuhang Hu, a PhD student at Columbia Engineering in Hod Lipson’s lab. Credit: John Abbott/Columbia Engineering

Columbia engineers build Emo, a silicon-clad robotic face that makes eye contact and uses two AI models to anticipate and replicate a person’s smile before the person actually smiles 

Robot, can you say 'Cheese'?

In this episode, we discuss how CalTech researchers have created bionic jellyfish to help us explore the oceans and better understand the impacts of climate change.

Podcast: Jellyfish Cyborgs Help Explore The Oceans & Solve Climate Change

The digital revolution has undeniably transformed how we access information and complete tasks, with laptops, tablets, and smartphones becoming ubiquitous companions in both our personal and professional lives. While these devices offer undeniable benefits, their constant use can also pose new challenges to our well-being, raising concerns about potential impacts on visual health and musculoskeletal function.One emerging area of concern is the intersection of presbyopia, a natural age-related decline in near vision, and the use of progressive lenses. These lenses, often referred to as 'no-line bifocals', &nbsp;provide wearers with a seamless transition between near and far vision, addressing the challenges of presbyopia. However, research suggests that the way we use progressive lenses, with their specific viewing zones, may subtly alter our head and neck postures, potentially leading to discomfort or even musculoskeletal disorders.To shed light on this issue, FREMAP, a leading Spanish mutual benefit association, embarked on a <a href="https://practicapreventiva.fremap.es/2023/02/09/uso-de-dispositivos-digitales-con-gafas-progresivas/" target="_blank" rel="noopener noreferrer">research</a> study to objectively assess the impact of progressive lenses on workplace ergonomics. Their primary objective was to quantify the visual and postural changes associated with using these lenses in a typical workstation environment. <img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwODM2NzM4NDQxLWVtaWFwLTEuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Worker wearing progressive lenses with the Xsens motion capture sensors to analyze postural changesTo achieve this objective, the research team, led by National Ergonomics Consultant at FREMAP Prevention, D. Antonio Emir Díaz Martínez, employed <a href="https://www.movella.com/products/motion-capture" target="_blank" rel="noopener noreferrer">Xsens Motion Capture technolog</a>y, specifically an upper body configuration with 11 strategically placed inertial sensors. This system was integrated with FREMAP's own ergonomics recording, analysis and representation software, utilizing <a href="https://www.movella.com/products/motion-capture/mvn-analyze" target="_blank" rel="noopener noreferrer">Xsens Analyze Pro</a> for data processing. This setup allowed for the accurate capture and analysis of human movement and posture data.Antonio Emir Díaz Martínez, commented: "The use of this system allows us to quantify, concisely, precisely, and without interference with normal working conditions, the postural requirements of the cervical spine in workplaces with screens for data visualization. This is thanks to having a software solution that removes the possible interferences caused by local magnetic fields."By leveraging Xsens Motion Capture, the FREMAP researchers were able to quantify the precise head and neck movements associated with using progressive lenses while interacting with a computer screen.The research involved monitoring the grazing and cervical spine movements of a worker wearing progressive glasses while they interacted with a computer workstation. To ensure standardized conditions, the upper part of the screen was positioned at eye level, maintaining a distance of 60 cm from the worker. Additionally, the worker's posture was controlled by having them maintain their back against the chair's backrest and their elbows bent at an angle of approximately 80 degrees.Research Findings and RecommendationsThe analysis revealed that participants maintained consistent neck extension throughout the study, exceeding recommended ergonomic limits. This posture is likely linked to the need to look through the lower portion of progressive lenses for optimal near vision. While neck turning remained within acceptable limits, occasional lateral tilts suggest further ergonomic adjustments may be necessary.Based on the findings, the research makes the following recommendations for progressive lens users.<ul><li>Screen Positioning:&nbsp;Ensure the screen is positioned correctly for optimal viewing. Adjust the viewing distance based on task and screen size (400-750 mm for common office monitors). Consider increasing font size for individuals with progressive lenses to increase viewing distance and minimize reliance on the lower lens segment.</li><li>Screen Height: For progressive lens users, reduce the screen height significantly compared to the standard recommendation of aligning the top of the screen with eye level. This helps avoid neck extension for viewing through the lower lens zone.</li><li>Document Holders: Utilize adjustable lecterns or document holders to facilitate switching between digital and printed materials, minimizing strain on eye accommodation.</li><li>Recovery Breaks:&nbsp;Encourage frequent breaks to rest the eyes and change posture, especially for those wearing progressive lenses.</li><li>Occupational Spectacles: For individuals with presbyopia and prolonged digital device use, consider occupational spectacles specifically designed for computer work.</li><li>Training and Awareness:&nbsp;Educate first-time progressive lens users about adaptation exercises and the importance of adjusting their workstation layout. Encourage them to adopt healthy postural habits and avoid extended periods of static posture at their workstation.</li></ul>By implementing these recommendations, individuals who rely on progressive lenses can create a more ergonomically friendly workspace and potentially mitigate the risks associated with prolonged computer use.This research project by FREMAP provides valuable insights into the potential impact of progressive lenses on workplace ergonomics. By utilizing advanced motion capture technology like Xsens, the study offers a quantifiable and objective perspective on this complex issue. The findings can help inform future research, guide the development of ergonomic interventions, and ultimately contribute to promoting healthy workplace practices for individuals reliant on progressive lenses.Xsens motion capture for ergonomics assessments<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwODM3MDc2NDU2LWVtaWFwLTIuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Accurate motion data: Xsens Awinda Motion Capture Technology featuring 18 inertial sensorsEnsuring proper workplace ergonomics is crucial for employee well-being, regulatory compliance, and increased productivity. This focus stems from the significant prevalence of musculoskeletal disorders (MSDs), often linked to poor ergonomics, affecting nearly 1.71 billion people globally.However, traditional assessment methods can be time-consuming and rely on subjective observations, potentially hindering accurate risk identification. Xsens Motion capture technology offers a compelling solution. Xsens captures objective and validated data on worker movements, eliminating subjectivity and increasing data collection efficiency. This empowers companies to swiftly identify potential hazards and make informed decisions regarding workplace design and modifications. Ultimately, this fosters safer and more productive workspaces, leading to a thriving and healthy working environment for all.<a href="https://www.movella.com/applications/health-sports/workplace-ergonomics" target="_blank" rel="noopener noreferrer">Learn more</a> about Xsens solutions for workplace ergonomics.&nbsp;

FREMAP uses Xsens motion capture to analyze the ergonomic impact of progressive lenses in the workplace and makes recommendations for improvement

Ergonomic impact of progressive lenses in the workplace

In this episode, we discuss a novel sticker capable of monitoring the health of organs in real time allowing for more successful organ transplants and catching signs of diseases earlier than ever!

Podcast: Sticker to Monitor Your Internal Organs

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/b5ad041a-a5dc-42cd-900b-390dca184186?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>A few years ago, a team of researchers working under Professor Stanisa Raspopovic at the ETH Zurich Neuroengineering Lab gained worldwide attention when they announced that their prosthetic legs had enabled amputees to feel sensations from this artificial body part for the first time. Unlike commercial leg prostheses, which simply provide amputees with stability and support, the ETH researchers’ prosthetic device was connected to the sciatic nerve in the test subjects’ thigh via implanted electrodes.This electrical connection enabled the neuroprosthesis to communicate with the patient’s brain, for example relaying information on the constant changes in pressure detected on the sole of the prosthetic foot when walking. This gave the test subjects greater confidence in their prosthesis – and it enabled them to walk considerably faster on challenging terrains. “Our experimental leg prosthesis succeeded in evoking natural sensations. That’s something current neuroprostheses are mainly unable to do; instead, they mostly evoke artificial, unpleasant sensations,” Raspopovic says.This is probably because today’s neuroprosthetics are using time-constant electrical pulses to stimulate the nervous system. “That’s not only unnatural, but also inefficient,” Raspopovic says. In a recently published paper, he and his team used the example of their leg prostheses to highlight the benefits of using naturally inspired, biomimetic stimulation to develop the next generation of neuroprosthetics.<h2>Model simulates activation of nerves in the sole</h2>To generate these biomimetic signals, Natalija Katic – a doctoral student in Raspopovic’s research group – developed a computer model called FootSim. It is based on data collected by collaborators in Canada, who recorded the activity of natural receptors, named mechanoreceptors, in the sole of the foot while touching different points on the feet of volunteers with a vibrating rod.The model simulates the dynamic behaviour of large numbers of mechanoreceptors in the sole of the foot and generates the neural signals that shoot up the nerves in the leg towards the brain – from the moment the heel strikes the ground and the weight of the body starts to shift forward to the outside of the foot until the toes push off the ground ready for the next step. “Thanks to this model, we can see how semsory receptors from the sole, and the connected nerves, behave during walking or running, which is experimentally impossible to measure” Katic says.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA5ODI0NDc4NjY1LWltYWdlLmltYWdlZm9ybWF0LjEyODYuNDg4NzEzNzM4LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">Restoring natural sensory feedback results in functional and cognitive benefits for leg prosthesis users. (Photograph: Pietro Comaschi)Restoring natural sensory feedback results in functional and cognitive benefits for leg prosthesis users.&nbsp;(Photograph: Pietro Comaschi)<h2 id="isPasted">Information overload in the spinal cord</h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;To assess how closely the biomimetic signals calculated by the model correspond to the signals emitted by real neurons, Giacomo Valle – a postdoc in Raspopovic’s research group – worked with colleagues in Germany, Serbia and Russia on experiments with cats, whose nervous system processes movement in a similar way to that of humans. The experiments took place in 2019 at the Pavlov Institute of Physiology in St. Petersburg and were carried out in accordance with the relevant European Union guidelines.The researchers implanted electrodes, connecting some to the nerve in the leg and some to the spinal cord to discover how the signals are transmitted through the nervous system. When the researchers applied pressure to the bottom of the cat’s paw, thereby evoking the natural neural response that occurs when a cat takes a step, the peculiar pattern of activity recorded in the spinal cord did indeed resemble the patterns that were elicited in the spinal cord when the researchers stimulated the leg nerve with biomimetic signals.By contrast, the conventional approach of time-constant stimulation of the sciatic nerve in the cat’s thigh elicited a markedly different pattern of activation in the spinal cord. “This clearly shows that the commonly used stimulation methods cause the neural networks in the spine to be flooded with information,” Valle says. “This information overload could be the reason for the unpleasant sensations or paraesthesia reported by some users of neuroprosthetics,” Raspopovic adds.<h2>Learning the language of the nervous system</h2>In their clinical trial with leg amputees, the researchers were able to show that biomimetic stimulation is superior to time-constant stimulation. Their work clearly demonstrated how the signals that mimicked nature produced better results: not only were the test subjects able to climb steps faster, they also made fewer mistakes in a task that required them to climb the same steps while spelling words backwards. “Biomimetic neurostimulation allows subjects to concentrate on other things while walking,” Raspopovic says, “so we concluded that this type of stimulation is more naturally processed and less taxing on the brain.”Raspopovic, whose lab forms part of the ETH Institute of Robotics and Intelligent Systems, believes that these new findings are not only relevant to the limb prostheses he and his team have been working on for over half a decade. He argues that the need to move away from unnatural, time-constant stimulation towards biomimetic signals also applies to a whole series of other aids and devices, including spinal implants and electrodes for brain stimulation. “We need to learn the language of the nervous system,” Raspopovic says. “Then we’ll be able to communicate with the brain in ways it really understands.”<h2>Information overload in the spinal cord</h2>To assess how closely the biomimetic signals calculated by the model correspond to the signals emitted by real neurons, Giacomo Valle – a postdoc in Raspopovic’s research group – worked with colleagues in Germany, Serbia and Russia on experiments with cats, whose nervous system processes movement in a similar way to that of humans. The experiments took place in 2019 at the Pavlov Institute of Physiology in St. Petersburg and were carried out in accordance with the relevant European Union guidelines.The researchers implanted electrodes, connecting some to the nerve in the leg and some to the spinal cord to discover how the signals are transmitted through the nervous system. When the researchers applied pressure to the bottom of the cat’s paw, thereby evoking the natural neural response that occurs when a cat takes a step, the peculiar pattern of activity recorded in the spinal cord did indeed resemble the patterns that were elicited in the spinal cord when the researchers stimulated the leg nerve with biomimetic signals.By contrast, the conventional approach of time-constant stimulation of the sciatic nerve in the cat’s thigh elicited a markedly different pattern of activation in the spinal cord. “This clearly shows that the commonly used stimulation methods cause the neural networks in the spine to be flooded with information,” Valle says. “This information overload could be the reason for the unpleasant sensations or paraesthesia reported by some users of neuroprosthetics,” Raspopovic adds.<h2>Learning the language of the nervous system</h2>In their clinical trial with leg amputees, the researchers were able to show that biomimetic stimulation is superior to time-constant stimulation. Their work clearly demonstrated how the signals that mimicked nature produced better results: not only were the test subjects able to climb steps faster, they also made fewer mistakes in a task that required them to climb the same steps while spelling words backwards. “Biomimetic neurostimulation allows subjects to concentrate on other things while walking,” Raspopovic says, “so we concluded that this type of stimulation is more naturally processed and less taxing on the brain.”Raspopovic, whose lab forms part of the ETH Institute of Robotics and Intelligent Systems, believes that these new findings are not only relevant to the limb prostheses he and his team have been working on for over half a decade. He argues that the need to move away from unnatural, time-constant stimulation towards biomimetic signals also applies to a whole series of other aids and devices, including spinal implants and electrodes for brain stimulation. “We need to learn the language of the nervous system,” Raspopovic says. “Then we’ll be able to communicate with the brain in ways it really understands.”<hr><h2 id="isPasted">Reference</h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;Valle G, Katic Secerovic N, Eggemann D, Gorskii O, Pavlova N, Petrini FM, Cvancara P, Stieglitz T, Musienko P, Bumbasirevic M, Raspopovic S: Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation. Nature Communications, 20 February 2024, doi: <a href="https://doi.org/10.1038/s41467-024-45190-6" target="_blank">external page10.1038/s41467-024-45190-6</a>

ETH researchers have developed a prosthetic leg that communicates with the brain via natural signals. (Photograph: Keystone)

Prostheses that connect to the nervous system have been available for several years. Now, researchers at ETH Zurich have found evidence that neuroprosthetics work better when they use signals that are inspired by nature.

Bio-inspired neuroprosthetics: sending signals the brain can understand

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/18c9c9fd-d774-46bc-87b8-fb1b0e7a5ae4?dark=false" class="fr-draggable" data-gtm-yt-inspected-9="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>Jellyfish can't do much besides swim, sting, eat, and breed. They don't even have brains. Yet, these simple creatures can easily journey to the depths of the oceans in a way that humans, despite all our sophistication, cannot.But what if humans could have jellyfish explore the oceans on our behalf, reporting back what they find? New research conducted at Caltech aims to make that a reality through the creation of what researchers call biohybrid robotic jellyfish. These creatures, which can be thought of as ocean-going cyborgs, augment jellyfish with electronics that enhance their swimming and a prosthetic "hat" that can carry a small payload while also making the jellyfish swim in a more streamlined manner.The work, published in the journal Bioinspiration &amp; Biomimetics, was conducted in the lab of John Dabiri (MS '03, PhD '05), the Centennial Professor of Aeronautics and Mechanical Engineering, and builds on his previous work augmenting jellyfish. Dabiri's goal with this research is to use jellyfish as robotic data-gatherers, sending them into the oceans to collect information about temperature, salinity, and oxygen levels, all of which are affected by Earth's changing climate."It's well known that the ocean is critical for determining our present and future climate on land, and yet, we still know surprisingly little about the ocean, especially away from the surface," Dabiri says. "Our goal is to finally move that needle by taking an unconventional approach inspired by one of the few animals that already successfully explores the entire ocean."<iframe width="640" height="360" src="https://www.youtube.com/embed/_ZfthP_7s5g?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-9="true" id="779481107" title="Robotic Jellyfish Explorers">&nbsp;</iframe>Media assets: Robotic Jellyfish ExplorersThroughout his career, Dabiri has looked to the natural world, jellyfish included, for inspiration in solving engineering challenges. This work began with early attempts by Dabiri's lab to develop a mechanical robot that swam like jellyfish, which have the most efficient method for traveling through water of any living creature. Though his research team succeeded in creating such a robot, that robot was never able to swim as efficiently as a real jellyfish. At that point, Dabiri asked himself, why not just work with jellyfish themselves?"Jellyfish are the original ocean explorers, reaching its deepest corners and thriving just as well in tropical or polar waters," Dabiri says. "Since they don't have a brain or the ability to sense pain, we've been able to collaborate with bioethicists to develop this biohybrid robotic application in a way that's ethically principled."Previously, Dabiri's lab implanted jellyfish with a kind of electronic pacemaker that controls the speed at which they swim. In doing so, they found that if they made jellyfish swim faster than the leisurely pace they normally keep, the animals became even more efficient. A jellyfish swimming three times faster than it normally would uses only twice as much energy.This time, the research team went a step further, adding what they call a forebody to the jellies. These forebodies are like hats that sit atop the jellyfish's bell (the mushroom-shaped part of the animal). The devices were designed by graduate student and lead author Simon Anuszczyk (MS '22), who aimed to make the jellyfish more streamlined while also providing a place where sensors and other electronics can be carried."Much like the pointed end of an arrow, we designed 3D-printed forebodies to streamline the bell of the jellyfish robot, reduce drag, and increase swimming performance," Anuszczyk says. "At the same time, we experimented with 3D printing until we were able to carefully balance the buoyancy and keep the jellyfish swimming vertically."To test the augmented jellies' swimming abilities, Dabiri's lab undertook the construction of a massive vertical aquarium inside Caltech's Guggenheim Laboratory. Dabiri explains that the three-story tank is tall, rather than wide, because researchers want to gather data on oceanic conditions far below the surface."In the ocean, the round trip from the surface down to several thousand meters will take a few days for the jellyfish, so we wanted to develop a facility to study that process in the lab," Dabiri says. "Our vertical tank lets the animals swim against a flowing vertical current, like a treadmill for swimmers. We expect the unique scale of the facility—probably the first vertical water treadmill of its kind—to be useful for a variety of other basic and applied research questions."<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA5NTIxNzc5NzI4LURhYmlyaS1MYWItTG9uZy1EaXN0YW5jZS1Td2ltbWluZ19Gb3JlYm9keTMubWF4LTE0MDB4ODAwLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">A biohybrid jellyfish descends through the three-story tank in which swimming tests were conducted. Credit: CaltechSwim tests conducted in the tank show that a jellyfish equipped with a combination of the swimming pacemaker and forebody can swim up to 4.5 times faster than an all-natural jelly while carrying a payload. The total cost is about $20 per jellyfish, Dabiri says, which makes biohybrid jellies an attractive alternative to renting a research vessel that can cost more than $50,000 a day to run."By using the jellyfish's natural capacity to withstand extreme pressures in the deep ocean and their ability to power themselves by feeding, our engineering challenge is a lot more manageable," Dabiri adds. "We still need to design the sensor package to withstand the same crushing pressures, but that device is smaller than a softball, making it much easier to design than a full submarine vehicle operating at those depths."I'm really excited to see what we can learn by simply observing these parts of the ocean for the very first time," he adds.Dabiri says future work may focus on further enhancing the bionic jellies' abilities. Right now, they can only be made to swim faster in a straight line, such as the vertical paths being designed for deep ocean measurement. But further research may also make them steerable, so they can be directed horizontally as well as vertically.The paper describing the work, "<a href="https://iopscience.iop.org/article/10.1088/1748-3190/ad277f" target="_blank">Electromechanical enhancement of live jellyfish for ocean exploration</a>," appears in the February 28 issue of Bioinspiration &amp; Biomimetics. Co-authors are Anuszczyk and Dabiri.

Jellyfish can't do much besides swim, sting, eat, and breed. They don't even have brains. Yet, these simple creatures can easily journey to the depths of the oceans in a way that humans, despite all our sophistication, cannot.

Building Bionic Jellyfish for Ocean Exploration

In this episode, we discuss the shortcomings of previous attempts at making flexible wearable sensors and how researchers at CalTech have addressed them to create high performance stress sensor stickers.

Stress Sensing Stickers

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/1e9bb08c-384a-4d12-983e-8af2e63c741b?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>MIT engineers have developed a small ultrasound sticker that can monitor the stiffness of organs deep inside the body. The sticker, about the size of a postage stamp, can be worn on the skin and is designed to pick up on signs of disease, such as liver and kidney failure and the progression of solid tumors.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3NzI0MzU5MjkzLU1JVC1TZWVpbmdTdGlmZm5lc3MtMDEtcHJlc3NfMC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">A small ultrasound sticker, worn on the skin, can monitor the stiffness of organs deep inside the body. The MIT-developed sensor could detect signs of disease such as liver and kidney failure, and the progression of solid tumors. Image: Courtesy of the researchersIn an <a href="https://science.org/doi/10.1126/sciadv.adk8426" target="_blank">open-access study appearing today</a> in Science Advances, the team reports that the sensor can send sound waves through the skin and into the body, where the waves reflect off internal organs and back out to the sticker. The pattern of the reflected waves can be read as a signature of organ rigidity, which the sticker can measure and track.“When some organs undergo disease, they can stiffen over time,” says the senior author of the paper, Xuanhe Zhao, professor of mechanical engineering at MIT. “With this wearable sticker, we can continuously monitor changes in rigidity over long periods of time, which is crucially important for early diagnosis of internal organ failure.”The team has demonstrated that the sticker can continuously monitor the stiffness of organs over 48 hours and detect subtle changes that could signal the progression of disease. In preliminary experiments, the researchers found that the sticky sensor can detect early signs of acute liver failure in rats.The engineers are working to adapt the design for use in humans. They envision that the sticker could be used in intensive care units (ICUs), where the low-profile sensors could continuously monitor patients who are recovering from organ transplants.“We imagine that, just after a liver or kidney transplant, we could adhere this sticker to a patient and observe how the rigidity of the organ changes over days,” lead author Hsiao-Chuan Liu says. “If there is any early diagnosis of acute liver failure, doctors can immediately take action instead of waiting until the condition becomes severe.” Liu was a visiting scientist at MIT at the time of the study and is currently an assistant professor at the University of Southern California.The study’s MIT co-authors include Xiaoyu Chen and Chonghe Wang, along with collaborators at USC.Sensing wobblesLike our muscles, the tissues and organs in our body stiffen as we age. With certain diseases, stiffening organs can become more pronounced, signaling a potentially precipitous health decline. Clinicians currently have ways to measure the stiffness of organs such as the kidneys and liver using ultrasound elastography — a technique similar to ultrasound imaging, in which a technician manipulates a handheld probe or wand over the skin. The probe sends sound waves through the body, which cause internal organs to vibrate slightly and send waves out in return. The probe senses an organ’s induced vibrations, and the pattern of the vibrations can be translated into how wobbly or stiff the organ must be.Ultrasound elastography is typically used in the ICU to monitor patients who have recently undergone an organ transplant. Technicians periodically check in on a patient shortly after surgery to quickly probe the new organ and look for signs of stiffening and potential acute failure or rejection.“After organ transplantation, the first 72 hours is most crucial in the ICU,” says another senior author, Qifa Zhou, a professor at USC. “With traditional ultrasound, you need to hold a probe to the body. But you can’t do this continuously over the long term. Doctors might miss a crucial moment and realize too late that the organ is failing.”The team realized that they might be able to provide a more continuous, wearable alternative. Their solution expands on an <a href="https://news.mit.edu/2022/ultrasound-stickers-0728" target="_blank">ultrasound sticker</a> they previously developed to image deep tissues and organs.“Our imaging sticker picked up on longitudinal waves, whereas this time we wanted to pick up shear waves, which will tell you the rigidity of the organ,” Zhao explains.Existing ultrasound elastrography probes measure shear waves, or an organ’s vibration in response to sonic impulses. The faster a shear wave travels in the organ, the stiffer the organ is interpreted to be. (Think of the bounce-back of a water balloon compared to a soccer ball.)The team looked to miniaturize ultrasound elastography to fit on a stamp-sized sticker. They also aimed to retain the same sensitivity of commercial hand-held probes, which typically incorporate about 128 piezoelectric transducers, each of which transforms an incoming electric field into outgoing sound waves.“We used advanced fabrication techniques to cut small transducers from high-quality piezoelectric materials that allowed us to design miniaturized ultrasound stickers,” Zhou says.The researchers precisely fabricated 128 miniature transducers that they incorporated onto a 25-millimeter-square chip. They lined the chip’s underside with an adhesive made from hydrogel — a sticky and stretchy material that is a mixture of water and polymer, which allows sound waves to travel into and out of the device almost without loss.In preliminary experiments, the team tested the stiffness-sensing sticker in rats. They found that the stickers were able to take continuous measurements of liver stiffness over 48 hours. From the sticker’s collected data, the researchers observed clear and early signs of acute liver failure, which they later confirmed with tissue samples.“Once liver goes into failure, the organ will increase in rigidity by multiple times,” Liu notes.“You can go from a healthy liver as wobbly as a soft-boiled egg, to a diseased liver that is more like a hard-boiled egg,” Zhao adds. “And this sticker can pick up on those differences deep inside the body and provide an alert when organ failure occurs.”The team is working with clinicians to adapt the sticker for use in patients recovering from organ transplants in the ICU. In that scenario, they don’t anticipate much change to the sticker’s current design, as it can be stuck to a patient’s skin, and any sound waves that it sends and receives can be delivered and collected by electronics that connect to the sticker, similar to electrodes and EKG machines in a doctor’s office.“The real beauty of this system is that since it is now wearable, it would allow low-weight, conformable, and sustained monitoring over time,” says Shrike Zhang,&nbsp;an associate professor of medicine at Harvard Medical School and associate bioengineer at Brigham and Women’s Hospital, who was not involved with the study. “This would likely not only allow patients to suffer less while achieving prolonged, almost real-time monitoring of their disease progression, but also free trained hospital personnel to other important tasks.”The researchers are also hoping to work the sticker into a more portable, self-enclosed version, where all its accompanying electronics and processing is miniaturized to fit into a slightly larger patch. Then, they envision that the sticker could be worn by patients at home, to continuously monitor conditions over longer periods, such as the progression of solid tumors, which are known to harden with severity.“We believe this is a life-saving technology platform,” Zhao says. “In the future, we think that people can adhere a few stickers to their body to measure many vital signals, and image and track the health of major organs in the body.”

“We used advanced fabrication techniques to cut small transducers from high-quality piezoelectric materials that allowed us to design miniaturized ultrasound stickers,” Xuanhe Zhao, professor of mechanical engineering at MIT, says. Image: Courtesy of the researchers

The sticky, wearable sensor could help identify early signs of acute liver failure.

This ultrasound sticker senses changing stiffness of deep internal organs

The adoption of healthcare monitoring devices that are both flexible and conform to the wearer have gained traction1. Spurred on by the need for remote care during the COVID-19 pandemic and technological advances in sensor accuracy, wearable health monitoring devices have become more ubiquitous in many areas of healthcare. In particular, there has been a rise in the development of wearable sensing and monitoring devices for telemedicine operations. Telemedicine has grown significantly in the last few years—and even more so during the COVID-19 pandemic when doctor-patient contact was limited—to remotely monitor patients in their own homes so hospitals could free up much-needed beds. While wearable technologies can be used in clinical environments to provide an analysis, much of their potential is in remote health monitoring.These wearable sensing devices typically make use of flexible materials, such as polymers, thin films, 2D materials and other nanomaterials. Health monitoring devices often consist of a flexible material that conforms to the wearer and is integrated with electronic components, including sensors, a power source—be it a battery, solar cell, or some other type of energy harvester like a nanogenerator—communication technologies if it transmits data to a central processing system, and any relevant circuitry.Building electronic components that are small and flexible enough to be used in wearable technologies is not that straightforward, and is why different nanomaterials—especially 2D materials—are often used to create the components because they fit the bill and can be easily integrated. But another approach is gathering interest: printing sensors—the most crucial aspects of a monitoring system—directly onto the wearable device.These printed sensors are sometimes made of 2D materials and other nanomaterials, but other materials can also be used as well. The ability to print sensors onto wearable health monitoring devices could pave a way to a much simpler and easier route to commercializing more wearable monitoring devices—especially if conventional, inexpensive, or easy-to-use printing technologies are used to print the sensor.<h2>Why Printed Sensors?</h2>While a range of advanced deposition and nanodeposition methods exist that can fabricate thin-film sensors on the substrate for wearable devices—often a soft polymer due to their flexibility and conformability—a number of biomedical sensors can be printed using screen printing techniques. Other techniques, such as inkjet and transfer printing, can be used as well, but screen printing is seen as the best option for printing sensors.Screen printing equipment is widely available, has a relatively low cost, and is easier to use than more advanced deposition methods, so it offers a much more scalable and commercially feasible route for using printed sensors in healthcare monitoring devices. Screen printing can also be used with many materials—from polymer solutions to conductive nanomaterial inks—so it is a versatile platform for printing a number of sensors.So, why print sensors instead of creating them through other manufacturing routes? Screen printing is a simple, fast, and efficient printing technique that can produce a large number of identical patterns in a single print. For large-scale operations and commercialization potential, screen printing can easily be adapted for mass production at a lower cost than other methods.From a performance perspective, screen printing provides high-resolution patterning and can print over large areas. The ability of screen printing to deposit material on demand in a given location also helps to reduce waste—especially on large scales—compared to traditional manufacturing methods because it is all done in a single step.There are, therefore, a number of manufacturing benefits with using printing methods. Beyond that, a greater design capability exists for health wearables because printing methods enable the production of sensors that are not only very thin but also provide the ability to print on the surface of the device. This approach is much simpler than trying to integrate devices into the material matrix of the wearable. You can also create a more customized sensor because you can print on demand, and the printing process can be changed to make a different sensor much easier than a typical manufacturing line.In terms of the materials compatible with screen printing, the scope is vast. Depending on the type of sensor being created, a whole host of materials can be used. On the one hand, a range of metals can be made into printable conductive inks to build the sensor. Common metals for wearable health sensors include gold, copper, platinum, nickel, aluminum, and silver. Beyond metals, a range of nanomaterial composites (graphene, carbon nanotubes composites), functional nanomaterial inks, and silver composites have all been used as the active sensing surface in printed health wearable sensors.The sensors also need a platform to be printed on. This often takes the form of a conductive polymer so that the sensor can better interact with the skin and the other components to provide higher sensitivity and reliability. PEDOT:PSS is the polymer platform that is most widely used for printed sensors, but other polymer materials include polyacetylene, polypyrrol, polyphenylene, poly (p-phenylene vinylene), and polythiophene polyaniline.<h2>The Printed Sensors of Interest in Healthcare Monitoring Applications</h2>Just as many materials can be used to create printed health sensors, many different types of printable sensors are used in health monitoring devices. Take, for example, strain-based sensors. Strain-based sensors measure a form of movement, and these wearable sensors are used in human-physiological signal monitoring and human-joint motion monitoring approaches.Another healthcare specialty measures different biomolecules and human signals. Non-strain-based sensors detect the biomolecule of interest directly or by directly measuring a physiological parameter that the patient exhibits. From a molecule-sensing perspective, a number of biomolecules in the blood can be detected, with glucose levels being a common one as well as the presence of sweat on a person’s skin. From a signal detection perspective, printed sensors can now detect respiration and heartbeat levels in a patient and provide remote electrocardiogram (ECG) monitoring.Another class of printed sensors for wearables is sensor arrays. In sensor arrays, multiple sensors work together to detect more complex issues or issues that require analysis from several stimuli angles. Sensor arrays are helpful in monitoring gait during walking, monitoring the sitting posture of wheelchair users, and monitoring the skin.Finally, there’s been advances in the development of printed temperature sensors for wearable health devices. Thermal sensing is a key area in disease detection because the body suffers thermal stresses when there is a disease present, and the rise in both skin and deep body temperature can be a primary indicator of a serious disease. Using printed temperature sensors, health wearables can detect a range of chronic diseases, such as cardiovascular, diabetic, and pulmonological diseases, as well as cancer.<h2>Conclusion</h2>Health monitoring wearables are gaining acceptance as an effective way to remotely measure many health factors of a patient. The most important aspect of these wearables is the sensing system that provides the analysis on the patient. For patients to be willing to wear the health monitoring device over an extended amount of time, the sensors and other components need to flex with the wearable component. While integrating flexible sensors is possible—for example, by using thin nanomaterials—printing sensors on the device’s surface is much easier, requires less material, and is much more scalable.A variety of printed health wearables are already in existence (commercially and academically. The printing methods discussed offer a route to achieve widespread distribution of health wearables. While many options are available, screen printing is the leading printing technology because it is highly versatile and can be used with many materials to create sensors that monitor different aspects of a person’s health—from heart rate to detecting a chance of a disease, to the different biomolecules in their blood, and many more in between.

The COVID-19 pandemic and advancements in sensor technology have led to the widespread adoption of wearable health monitoring devices, particularly for telemedicine, to facilitate remote patient monitoring.

Printable Sensors: A Key Technology for Health Wearables?

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/437b67d4-99c8-455a-9ae6-e487b81825a1?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>In the latest of a series of innovative designs for wearable sensors that use sweat to identify and measure physiological conditions, Caltech's Wei Gao, assistant professor of medical engineering, has devised an "electronic skin" that continuously monitors nine different markers that characterize a stress response. Those wearing this electronic skin—a small, thin adhesive worn on the wrist, called CARES (consolidated artificial-intelligence-reinforced electronic skin)—are free to engage in all their normal daily activities with minimal interference during testing, which allows for the measurement of both baseline and acute levels of stress.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA2NTEyNDkyMDc2LUdhb19XZWktU3RyZXNzLVN3ZWF0LVNlbnNvci01LVdFQi53aWR0aC00NTAgKDEpLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib">Stress is a slippery concept. We talk about "feeling stressed" or a situation "being stressful," and we may attach stress to physical symptoms: "I have a stress headache" or "I'm grinding my teeth at night. It must be stress." The term stress can apply to all sorts of feelings, symptoms, behaviors, and experiences.Hans Selye, a physician and chemist born in Vienna in 1907, was the first to define stress as a medical condition. Struck by the similar complaints—such as tiredness, low appetite, and lack of motivation—that he heard from patients suffering from very different illnesses, Selye speculated that all of the patients were responding to what they had in common: being sick. He defined stress as a "nonspecific response of the body to any demand."Stress may be experienced positively as excitement or energy, or negatively as shock or anxiety. But however stress may be experienced emotionally, it is now widely agreed that depending on its severity and duration, both acute and chronic stress can damage our physical and mental health, and reduce our ability to function as we would like.Because stress is, as Selye described it, "nonspecific," there is no single biomarker available to tell us definitively whether or how much a person is stressed. However, stress generates a constellation of bodily reactions that, taken together, can provide a measure of stress independent of self-reports. Gao is monitoring this constellation with CARES.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA2NTEyNDI2MzM3LUdhb19XZWktU3RyZXNzLVN3ZWF0LVNlbnNvci00LVdFQl8zSW1tM1pKLndlYnAiLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">A sweat sensor worn on the wrist, lifted to show the thinness of the device. Credit: Wei Gao and Changhao Xu"When a person is under stress, hormones like epinephrine, norepinephrine, and cortisol are released into the bloodstream," explains Gao, who is also an investigator with the Heritage Medical Research Institute and a Ronald and JoAnne Willens Scholar. "Sweat becomes rich with metabolites like glucose, lactate, and uric acid, and electrolytes like sodium, potassium, and ammonium. These are substances we have measured before using <a href="https://www.caltech.edu/about/news/new-wearable-sensor-detects-even-more-compounds-in-human-sweat" target="_blank">microfluidic sampling on a wearable sweat sensor</a>. What is new in CARES is that sweat sensors are integrated with sensors that record pulse waveforms, skin temperature, and galvanic skin response: physiological signals that also indicate stress in predictable ways."New materials further boost the performance of CARES. Though previously used materials for sweat sensors could be produced efficiently via inkjet printing and were capable of accurate measurement of even very scarce compounds, the materials gradually broke down in the presence of bodily fluids. The introduction of a nickel-based compound helps to stabilize the enzymatic-based sensors, such as those that detect lactate or glucose, as does a new polymer added to the ion-based sensors, which detect biomarkers like sodium or potassium. "Adding these new materials greatly enhances the sensor stability during long-term operation," Gao reports. Like previous sweat sensors, CARES can be battery powered and can wirelessly communicate with a phone or computer via Bluetooth.Another important innovation with CARES is the addition of machine learning. Because stress comes in many different forms and stimulates a complex response affecting many different bodily systems, interpreting a wealth of data accurately is key to the usefulness of CARES and other sensors. Experiments inducing stress in subjects wearing the CARES device demonstrated that the sensor accurately measures the interrelatedness of physiological (such as pulse) and chemical (such as glucose) biomarkers. Subjects also answered questionnaires to self-report their feelings of anxiety and psychological stress before and after exposure to stressful situations like vigorous exercise or intense video gameplay. Data showed clear correlations between self-reports of stress and its physicochemical correlates as measured by CARES."High levels of stress and anxiety caused by demanding work environments, such as those experienced by soldiers or astronauts, can significantly affect performance," Gao notes. "Early detection of the severity of stress allows for timely intervention. Our wearable sensor, combined with machine learning, has the potential to provide real-time stress-level insights."The paper describing the CARES device, titled "A physicochemical sensing electronic skin for stress response monitoring," appears in the January 19 issue of Nature Electronics. Co-authors are Changhao Xu (MS '20), Yu Song, Juliane R. Sempionatto, Samuel R. Solomon (MS '23), You Yu, Roland Yingjie Tay, Jiahong Li, Wenzheng Heng (MS '23), Jihong Min (MS '19), and Alison Lao of Caltech; Hnin Y. Y. Nyein of Hong Kong University of Science and Technology; and Tzung K. Hsiai and Jennifer A. Sumner of UCLA.

In the latest of a series of innovative designs for wearable sensors that use sweat to identify and measure physiological conditions, Caltech's Wei Gao has devised an "electronic skin" that continuously monitors nine different markers that characterize a stress response.

Measuring Stress

Just a year ago, on November 29, 2022, Enchanted Tools announced its entrance into the world of robotics with the introduction of its humanoid robot, Mirokaï. With the goal of producing 100,000 robots by 2032, Enchanted Tools' engineers are working tirelessly to bring their dream to life. Miroki has traveled from Paris to Las Vegas to Tokyo, gaining popularity and acclaim along the way. Laurent Vasse, Enchanted Tools' Industrial Director, shared the resources and technological support provided by maxon teams to help meet these challenges.<h2 dir="ltr">Enchanted Tools: useful robots to re-enchant the world.</h2>Enchanted Tools is a start-up with the goal of transforming the field of robotics. To make this possible, they have developed robot-characters called Mirokaï, which weigh 28kg and stand at 1.23m tall. These robots are designed to be both endearing and useful, with a unique appearance that combines animal and manga characteristics. The Mirokaï serve three main purposes.<ul><li dir="ltr">Move autonomously, thanks to an orbital globe on which they are perched.</li><li dir="ltr">Grip objects, using a universal handle that gives them a 97% success rate.</li><li dir="ltr">Interact with humans, in a timely manner, by being able to understand and execute voice commands.&nbsp;</li></ul><blockquote><blockquote>"The Mirokaï have been designed with simplification in mind: simplifying input, simplifying navigation and simplifying interaction, to help those who help on a daily basis, while providing ethical answers to today's robotics and AI challenges." says Jérôme Monceaux, CEO of Enchanted Tools.</blockquote></blockquote>Mirokaï robots are capable of carrying loads up to 3kg, which makes them suitable for various sectors such as hospitals, hotels, airports, and restaurants. These robots can relieve staff from performing the most tedious and physically demanding logistical tasks. What sets these robots apart from others is their animation-inspired design, and they are programmed to interact with people emotionally to enhance their adaptability.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyNTAzNTczODU4LVNlzIFxdWVuY2UgMTEuMDBfMjhfMTNfMjcucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">The Mirokaï robot character weighs 28kg and is 1.23m tall.<blockquote>“Since the first prototype was presented to the press, we have successfully developed a dozen demonstrators, which have enabled us to validate the robot’s impact, particularly with the help of healthcare professionals.” explains Laurent Vasse, Industrial Director at Enchanted Tools.</blockquote>Enchanted Tools' 70 engineers are now moving on to industrialization after a phase of concurrent engineering to strike the perfect balance between time-to-market, performance, and price.Open urban factory project to revolutionize robotic industrializationIn 2024, the Mirokaï will become a reality as the first pilot line is implemented. This will allow the production of approximately 50 robots by the end of the year. Previously, the R&amp;D engineers had designed and assembled demonstrators in the R&amp;D offices. However, with the introduction of the pilot line, the robot assembly process can be designed under conditions that closely mimic the industrial model. Laurent Vasse provided this information.Enchanted Tools is planning to open a factory in the heart of Paris. The company wants to show that robotics can re-enchant the world instead of dehumanizing it. The factory will not only produce robots but also introduce the world of robotics, mechatronics, and AI to people. According to Laurent Vasse, the company's goal is to change people's beliefs about this industry and democratize it. They hope to inspire people to pursue careers in this field as well.Within the factory Enchanted Tools there will be a broad range of activities and opportunities for engagement. Including:&nbsp;<ul><li dir="ltr">Industrial area,&nbsp;where assembly operations can be mastered.</li><li dir="ltr">Maintenance and assistance, where Enchanted Tools customers can benefit from the support they need once the robots are on the market.</li><li dir="ltr">R&amp;D&nbsp;Centre&nbsp;where Enchanted Tools engineers further develop the company's know-how.</li></ul>The factory is scheduled to open its doors in the summer of 2024, when all media attention will be focused on Paris, for the Olympic Games."We imagined this concept of an urban factory as one that could be replicated in other parts of the world, where we encounter the same issues of development, brand awareness, and robot maintenance. We therefore plan to duplicate this concept in North America, China, or Japan, to support our commercial development with this type of entity, which will combine all the skills we need to deploy in these regions" further explains Laurent Vasse.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyNTAzNzkwNTM4LW1heG9uIEVuY2hhbnRlZCBUb29scyBCdXJlYXUgZXR1ZGVzIDIucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">maxon Engineers worked closely with the Enchanted Tools team to solve technical challenges.<h2 dir="ltr" id="isPasted">100,000 robots in 10 years</h2>The pilot-line aims to produce around 50 robots in 2024, then 200 - 300 units in 2025. From 2026 onwards, Enchanted Tools is set to use a larger factory to produce a thousand robots a year, then ramp up production to 100,000 robots by 2032. "From the start, our goal has been to produce robots in large quantities, on a massive scale. This means having working methods, in terms of development and industrialization, that are revolutionary for the world of robotics”, explains Laurent Vasse. For the teams at Enchanted Tools, the challenge is to find the right balance between improving control and retaining a form of agility. In other words, Enchanted Tools strives to retain the flexibility that is the strength of start-ups, while applying robust methodologies worthy of more mature industries, to successfully initiate the industrialization phase.&nbsp;<blockquote>"To succeed in this challenge, we needed partners like maxon, capable of following us in this way, with excellent technological mastery and the ability to adapt and buildup in industrialization,", says Laurent Vasse, Industrial Director of Enchanted Tools.</blockquote><h2 dir="ltr">maxon x Enchanted Tools: strong collaboration brings the project to life.</h2>From the start of the project, Enchanted Tools' teams worked hand in hand with precision mechatronic system company, maxon France. Maxon assisted Enchanted Tool's to select the perfect drive system, size the products correctly, and customize certain elements according to the current and future needs of their project. "Right from the start, we were thinking in terms of industrialization and volume", says Kévin Schwartz, sales engineer for maxon France. He continues: "There's a huge gap between current production volumes and projections for the coming years. Thanks to the maxon group's industrial volumes and our production facilities, we were able to be extremely reactive, since these products were already in our catalog, and we were able to make the necessary customizations.”<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAyNTA0MDE3MTA5LU1heG9uIEZyYW5jZSAtIDI3IEp1aW4gMjAyMy00OTIuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib">The prototypes are tested against a variety of constraints.&nbsp;The maxon team then helped Enchanted Tools with product sizing and the choice of motorization ranges, taking into account the technical constraints and very tight deadlines required to present this new robot. EC-i 40 motors with planetary gearboxes were chosen for the Ball Bot, while ECX brushless motors with a diameter of 22mm are used for the orbital axes.To control industrialization, the maxon and Enchanted Tools project teams worked on different categories of prototypes (A, B and C). Each prototype is tested against functional, design, service life, and normative constraints, moving toward the final product and production, this approach enables the teams to anticipate the product's maturity.&nbsp;<blockquote>"The advantage of this approach is that it's robust when it comes to mass production. We go through all the design validation stages, to eliminate as many risks as possible, and then be able to calmly launch large volumes for industrialization", adds Kévin Schwartz.</blockquote>Thanks to the technological support provided by <a href="https://www.maxongroup.fr/maxon/view/content/index" target="_blank" rel="noopener noreferrer">maxon France</a>, the Enchanted Tools teams were able to move ahead quickly with industrialization. This partnership is one crucial step towards the realization of the Mirokaï project, which is set to influence the robotics landscape.&nbsp;

A year ago, French company Enchanted Tools unveiled its prototype humanoid robot, Mirokaï. The ambitious team plans to produce 100,000 robots by 2032. 



Building a humanoid robot in under a year

Science fiction films portray the idea relatively simply: the terminator – who either tries to destroy or rescue humanity – is such a perfect humanoid robot that in most cases it is superior to humans. But how well do humanoid robots perform nowadays away from the cinema screen? Precisely this question is addressed by a new study drawn up by lead author Robert Riener, Professor of Sensory-Motor Systems at ETH Zurich and founder of the <a href="https://cybathlon.ethz.ch/en" target="_blank">Cybathlon</a>, that is being published today in the robotics journal Frontiers in Robotics and AI. &nbsp;<iframe width="640" height="360" src="https://www.youtube.com/embed/u9nKDxvTMeY?&amp;wmode=opaque&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true">&nbsp;&nbsp;&nbsp;&nbsp;</iframe>Digit is a humanoid robot designed to move more dynamically than conventional robots. (Video: Agility Robotics)<h2>Comparing apples with apples</h2>The first scientific challenge was to develop criteria that permit a meaningful comparison between humans and machines. An industrial robot painting car bodies on a production line does this faster, for longer and more precisely than a human. It is especially developed for this but also does not have any other abilities.Riener therefore excluded such robots from the study: “We humans shape our environment according to our criteria and needs. If robots are to support us in a meaningful way, they need to work in this manmade environment. We therefore quickly arrived at robots that are similar to humans, at least anatomically.” It is for this reason that Riener exclusively examined humanoid robots for the study and integrated 27 relevant specimens into his research.Yet the researchers also defined certain selection criteria within this robot type. “For example, for a robot that has rollers rather than legs it would be fairly easy to roll faster than a human can run – but we didn’t want to compare apples with pears,” explains Riener. Only those robots were therefore selected that had two or four legs so that they were also able to climb steps. They also need to have a slim figure in order to pass through doors, and a certain height (at least 50 cm) with arms and hands (or extendable by arms and hands) so that they can also pick up objects on a tray or shelf. In order to be able to work with and support humans, they should also be quiet and not give off any exhaust emissions. &nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699581467325-image1.imageformat.lightbox.1055172521.jpg" style="width: 766px;" class="fr-fic fr-dib">ANYmal is a four-legged robot for the inspection and maintenance of technical systems. (Photograph: Robotic Systems Lab / ETH Zurich)<h2 id="isPasted">Robots clearly better – in terms of components</h2>The initial result surprised even the researcher: if one compares the individual components of machines and humans such as microphones with ears, cameras with eyes or drive systems with muscles, the technical components always fare better in terms of key sensory-motor properties. These days, for instance, carbon fibres are used, which are harder than bones. If we disregard other properties of the human bone, such as the fact that it is self-healing, the technical solution is clearly superior in terms of mechanical features. The baffling thing, as the ETH professor explains, is as follows: “The question that arises is why we are not able today to construct a robot from these high-quality components that has better powers of movement and perception than humans.”Which brings us to the second result of this comprehensive study: if we consider the activities that humans and machines are asked to carry out, humans are generally superior to robots. Although humanoid robots are also able to walk and run, if we set walking or running speed in relation to body dimensions, weight or energy consumption, most robots are no longer able to keep pace. At 6.1 metres per second, robot MIT-Cheetah runs faster than a jogging human and accordingly lives up to its name. However, the four-legged robot has a high energy consumption (973 watts) and is also only deployed under laboratory conditions. Humans also significantly outperform robots in terms of endurance versus operating time. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;<h2>Karate Kid with stiff joints<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699581515083-image.imageformat.textdouble.19354851.jpg" style="width: 304px;" class="fr-fic fr-dib">Humanoid iCub in child size from 2009. (Photograph: IIT-Istituto Italiano di Tecnologia)</h2>Robots benefit for certain functions from their precision. “For example, when balancing on one leg, robots can easily stiffen their joints, while humans tend to wobble a bit – which costs considerably more energy. Robots can also precisely recognise their joint angles and repeat movements very accurately, which is pretty impressive and somewhat reminiscent of Karate Kid,” says Robert Riener.The results are more mixed for another movement function – picking up objects: while robots can pick up objects extremely quickly, they are not yet able to outdo us regarding our many different hand movements and the manipulative skills of our fingers. And another weakness of robots emerges with regard to various movements such as swimming, crawling and jumping as they are only able to perform some of these movements. By contrast, most humans are easily capable of performing and combining several of these movements. Playing football is cited in the new study as an example of this: machines are still a long way from dribbling, heading or analyse and interprete the strategy of the other players. &nbsp;&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699581594040-1699581594040.png" style="width: 766px;" class="fr-fic fr-dib"><h2 id="isPasted">Robots can support us in the future</h2>Are humanoid robots today therefore still just a gimmick? “No, the progress made by robotics in recent years is incredible. We wish to have robots around us so that they can help us with difficult or dangerous tasks. However, our manmade environments are very complex, and it’s therefore not so easy for robots to function here autonomously and without error. Nevertheless, I’m confident that with the powerful technical components that are available we will soon be able to construct more intelligent robots that are capable of interacting with us humans better,” says Riener. An important next step according to Riener is to go to greater lengths in terms of system engineering and automatic control technology in order to combine the existing powerful components better.Deployment would then be conceivable, for example, in nursing and home care, the construction industry or in the household – i.e. wherever support is urgently needed in order to relieve staff and to support people with limited mobility, for instance.<hr><h2 id="isPasted">Reference</h2>Riener, R., Rabezzana, L., Zimmermann, Y: Do Robots Outperform Humans in Human-Centered Domains? Frontiers, Volume 10, November 2023, doi: <a href="https://www.frontiersin.org/articles/10.3389/frobt.2023.1223946/abstract" target="_blank">external page10.3389/frobt.2023.1223946</a>

A new ETH study compares 27 humanoid robots with humans and comes to the conclusion that while robots have better components, they are still not capable of achieving as much. However, according to the authors of the study, the machines are catching up.

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