This article originally appeared in <a href="https://engineering.wustl.edu/news/2023/Brain-machine-interfaces-for-insects-to-study-principles-of-odor-guided-navigation.html" target="_blank" rel="noopener noreferrer">McKelvey School of Engineering</a> and has been republished with permission.<hr><iframe width="640" height="360" src="https://www.youtube.com/embed/dBNOGbF-e7E?&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"></iframe>The locust follows a pleasant scent on a treadmill. (Credit: Raman lab)The inviting smell of a freshly baked cookie immediately triggers a motor response to search for the source of that smell. Often the cookie can be easily found.This everyday event that we perform without a thought is an amazing feat that combines our superior ability to smell the cookie and computational prowess to determine the directions to move toward the cookie. Robots that possess similar capabilities are yet to be developed as the basic biological principles that are needed to perform this task are yet to be fully understood. &nbsp;The ability to study neural responses in behaving insects is essential to understanding the robust solutions biological systems have developed for several engineering problems. For example, locusts have survived for at least 8 million years — longer than humans have been on this planet — in nearly all parts of the earth. Their many remarkable capabilities include seeing, hearing and smelling things that humans cannot sense, jumping multiple times their body length, the uncanny ability to fly up to 100 kilometers a day, and switching between solitary and menacing swarms phases as needed for survival. They use these capabilities to find food, avoid predators, propagate their species, and do all things necessary to keep them alive. Researchers in the McKelvey School of Engineering at Washington University in St. Louis have long sought to understand the power of the locusts’ sensing, computing and locomotory capabilities.Barani Raman, professor of biomedical engineering in the McKelvey School of Engineering, is leading a multidisciplinary team to study how the locust brain transforms sensory input into behavior with a four-year, $4.3 million grant from the National Science Foundation’s Integrative Strategies for Understanding Neural and Cognitive Systems (NCS) program. The grant converges years of research in Raman’s lab with that of his longtime WashU collaborators, including Shantanu Chakrabartty, professor of electrical &amp; systems engineering, and Srikanth Singamaneni, professor of mechanical engineering &amp; materials science, as well as Alexandra Rutz, assistant professor of biomedical engineering, and Yehuda Ben-Shahar, professor of biology, also at WashU.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1697685410077-ezgif-5-9129b96817.jpg" style="width: 766px;" class="fr-fic fr-dib">Researchers in the McKelvey School of Engineering have long sought to understand the power of the locusts’ sensing, computing and locomotory capabilities. With a $4.3 million grant from the National Science Foundation, they will converge that research to develop a “cyborg,” or mobile robot or drone, that can mimic the locusts’ behaviors. (Credit: Raman lab)“Insects are an engineering marvel,” Raman said. “They possess diverse sensing modalities and locomotory responses yet contained in such a small package. We want to engineer tools to study the amazing capabilities of these relatively simpler organisms.”The research brings together Washington University’s strengths in neural engineering, integrated circuits, biomaterials, synthetic biology and genetic engineering to understand how the insects use olfactory cues to navigate toward an odor source, which could potentially be used for various applications, such as detecting gas left on in the kitchen or as the proverbial canary in the coal mine to test spaces for hazardous chemicals. In 2024, the team plans to launch the first-of-its-kind Center for Cyborg and Biorobotics Research (CyBoR) to formally conduct the research.&nbsp;The team plans to study the neural response in the locusts’ brains by having the locusts follow a specific odor on a specially built treadmill while walking on a foam ball and while flying in a wind tunnel. By studying their movements and neural activity in the brain in response to these odors, the team can process the information using a custom microchip to develop a “cyborg,” or mobile robot or drone, that can mimic the locusts’ behaviors. They also aim to augment the locusts’ ability to detect certain odors over others.“Nature already has endowed this organism with various capabilities, so why not understand and augment those capabilities using synthetic mechanisms?” asked Chakrabartty, whose expertise is in sensors and integrated circuits. “Ultimately, our goal is to design a completely synthetic system that has similar remarkable capabilities.”While the team has already joined forces to create recording instruments and nanomaterials to manipulate neural and behavioral responses, they will continue to improve on those as they develop the bio-hybrid and mobile robotic systems.&nbsp;“One of the important challenges in these studies is the limited stability of the neural recording and stimulation electrodes and interfaces over a long period,” said Singamaneni, whose expertise is in novel bio- and nanomaterials. “We aim to design and realize novel anti-inflammatory electrodes and biointerfaces that will enable stable long-term neural recording and stimulation.”Previously, <a href="https://engineering.wustl.edu/news/2016/Engineers-to-use-cyborg-insects-as-biorobotic-sensing-machines.html" target="_blank">the research team developed a miniature “backpack”</a> containing sensors that recorded the locusts’ brain activity when exposed to the odors. However, the existing backpack is too heavy for the locusts to wear while flying, so the team will work to reduce its weight.At Washington University, the research is underway in a state-of-the-art CyBoR facility that includes the habitat for the locusts, the treadmill, the wind tunnel, specialized microscopes, and space for visiting researchers as well as for visitors interested in learning about the insects. WashU students also will be included in the research as well as students from the community through various outreach programs.&nbsp;Other co-investigators include Alper Bozkurt, distinguished professor of electrical &amp; computer engineering at North Carolina State University, who will lead efforts on instrumentation for navigation control; Sawyer Fuller, assistant professor of mechanical engineering at the University of Washington, who will lead efforts to build miniaturized robots that incorporate both biological and engineering elements; and Nabil Imam, assistant professor of computational science and engineering at Georgia Tech, who will lead the development of neuromorphic algorithms and hardware in the bio-hybrid and robotic systems.

Barani Raman, professor of biomedical engineering in the McKelvey School of Engineering, is leading a multidisciplinary team to study how the locust brain transforms sensory input into behavior with a four-year, $4.3 million grant from the National Science Foundation’s Integrative Strategies for Understanding Neural and Cognitive Systems (NCS) program. 

Brain-machine interfaces for insects to study principles of odor-guided navigation

<h2 dir="ltr" id="isPasted">Tried and tested (and free)</h2>Biomimetics is the method by which scientists borrow successful ideas from nature to use in their own inventions. The advantage of this approach is that the solutions found among animals and plants are not subject to any patent. And over countless millennia, there are certain structures and mechanisms in nature that have allowed all sorts of living things to survive in various conditions. Thus, developers can rely on nature&rsquo;s best ideas, modify them as needed, and create robots that resemble beings we&rsquo;re already familiar with.<blockquote>&ldquo;For instance, there&rsquo;s a German company named Festo that specializes in various biomimetic solutions. They have a kangaroo robot that, just like the real thing, conserves energy after a jump and uses it for the next one. There are other notable inventions: the well-known Spot robot-dogs, worm-like medical robots, or even drug delivery bots modeled after fish. Some specialists develop mechanisms based on plant life &ndash; plantoids. But that&rsquo;s still a work in progress and it&rsquo;ll be some time before you can buy one in a store,&rdquo; explains Pavel Kovalenko, an associate professor at the Faculty of Control Systems and Robotics.</blockquote><h2 dir="ltr" id="isPasted">More ground to cover</h2>Nevertheless, the biomimetic method suffers from several limitations. Firstly, scientists have not been successful in recreating the principles or developing materials that would allow them to fully replicate certain species. Take geckos: these lizards&rsquo; paws are covered with microscopic adhesive hairs that can stick to any smooth vertical surface and traverse it. But researchers are yet to create a similar technology that would be suitable for industrial production.<blockquote>&ldquo;When we try to create the same product using nanolithography, the hairs come out different: not splayed like they should be, but rather conical or simply crudely shaped. Because of this, the adhesion is not adequate. In addition, artificial materials cannot self-clean and, therefore, lose their stickiness. It&rsquo;s like a piece of duct tape that you apply and tear off again and again,&rdquo; says Pavel Kovalenko.</blockquote>The second limitation of biomimetics is the scalability of natural mechanisms: as a rule, the ideas used at nanoscale are not always reproducible in macroscale. This forces researchers to look for other solutions to applied problems. For instance, instead of a robotic gecko, they will also create a snail that can climb vertical surfaces.Last but not least, for robots to function as animals, researchers have to truly synchronize their control system, its components, and parts of the robot. According to Pavel Kovalenko, this can be achieved when both the software and the engineering aspects of the robot are developed by a single team with a clear view of their final outcome.&nbsp;<h2 dir="ltr" id="isPasted">A robotic zoo at ITMO</h2>Despite all these challenges, students and graduates of ITMO&rsquo;s Faculty of Control Systems and Robotics are actively engaged in biomimetics, having already completed several stages of their research. First, they analyzed the behavior, body structure and functions of living organisms, and then based on this step decided which body parts they should recreate in their work. They have also selected flexible materials resembling existing animals. At the next stage, the researchers performed calculations, chose the digital components and motors for the robot, and developed the necessary software. As a result, they have already created several model robotic animals.For instance, ITMO graduate Georgy Larionenko developed a waterproof robotic fish with a moving tail that works on two magnets. A servomotor inside the waterproof body activates the first magnet, which in its turn activates the second one that is connected to the fluke. This way, by moving its tail in the water, the robotic fish can swim &ndash; both in fresh and salty water, as experiments have shown. The robot can be useful for gauging the parameters of the water and the ocean floor in various conditions, including in the arctic region.&nbsp;<iframe src="https://www.youtube.com/embed/fYqbsCFRuS0?&wmode=opaque&rel=0&enablejsapi=1&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" style="width: 768px; height: 429px;"></iframe>A team of three graduates, Oksana Shuraeva, Anastasia Yusupova, and Anton Kovalenko, has developed a robotic snail. It can crawl down inclined surfaces by intermittently extending and retracting its &ldquo;paws,&rdquo; two spirals with plates attached to them. In order to guide the robot in the necessary direction, a servomotor, located in its shell, positions the snail&rsquo;s head at the needed angle, so that the rest of its body can follow suit. One application of this invention is window cleaning &ndash; the snail will leave a trail of detergent behind.Elizaveta Shelukhina, another ITMO graduate, wanted to make a device that will be protected from its environment. She could take inspiration from several animals, including turtles, hedgehogs, and armadillos, but eventually decided to settle on the latter, creating the concept for robotic armadillo. When the robot senses that something is falling on it or if someone kicks it, it rolls into a ball to protect its silicon insides. When the external influence ends, the robot unrolls back into its full length. Such robotic armadillos can come in handy in rescue missions, when there is a high risk of buildings collapsing.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1665655602540-1282503.jpg" style="width: 766px;" class="fr-fic fr-dib">Robotic snail. Image courtesy of the Faculty of Control Systems and Robotics&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1665655652013-1282504.jpg" style="width: 766px;" class="fr-fic fr-dib">The snail&rsquo;s locomotion mechanism includes two spirals with plates attached to them. The spirals are activated by two D41AB12 DC motors and when climbing an inclined surface the snail&rsquo;s front part is controlled by an FS5106B servomotor. Image courtesy of the Faculty of Control Systems and Robotics&nbsp; &nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1665655682130-1282501.jpg" style="width: 766px;" class="fr-fic fr-dib">The concept of a protected armadillo robot developed by Elizaveta Shelukhina. When hit by something, the robot rolls into a ball to protect its insides. Photo by Dmitry Grigoryev, ITMO.NEWS&nbsp; &nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1665655703530-1282502.jpg" style="width: 766px;" class="fr-fic fr-dib">The robotic fish presented at the Robotex youth robotics contect. Image courtesy of the Faculty of Control Systems and Robotics&nbsp; &nbsp;These days, students at the faculty are also developing various robotic animals. For example, Maged Mohamed, a second-year student in the Robotics and Artificial Intelligence Master&rsquo;s program, researches biomimetics to come up with his own prototype of a waterproof fish that will also resist the pressure deep underwater to collect samples of the bottom and water for analysis.&nbsp;<hr>Translated by&nbsp;<a data-saferedirecturl="https://www.google.com/url?q=https://news.itmo.ru/en/profile/30/&source=gmail&ust=1665742142569000&usg=AOvVaw3TxK7CnbdCJBWzW22ae5a2" href="https://news.itmo.ru/en/profile/30/" id="isPasted" rel="noopener noreferrer" target="_blank">Vadim Galimov</a> and <a href="https://news.itmo.ru/en/profile/51/" rel="noopener noreferrer" target="_blank">Catherine Zavodova</a>, and originally published by <a data-saferedirecturl="https://www.google.com/url?q=https://news.itmo.ru/en/&source=gmail&ust=1665742142569000&usg=AOvVaw2LChR-pA6lYpYiNzCB_TIH" href="https://news.itmo.ru/en/" target="_blank">ITMO.NEWS</a>

Boston Dynamics’ Spot, bionic kangaroos and even ants – biomimetics allows us to replicate almost any living thing. But why do roboticists look to animals for inspiration, what do they do at ITMO, and how do you make a robot act “natural”?

Biomimetics: The Science of Robo-Animals

In this episode, we talk about how engineers inspired by some of biology&rsquo;s most miniature wonders (like dandelions&#39; seeds and microorganisms&#39; cilia) are using their knowledge to make major breakthroughs in biosensing, robotics, biomedical engineering, and more. &nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/10c09f29-5a05-4710-b0e0-b25e0d139652?dark=false" class="fr-draggable" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true"></iframe><hr>This podcast is sponsored by <a href="https://www2.mouser.com/" id="isPasted" rel="nofollow" target="_blank">Mouser Electronics</a>. &nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1656328852054-Mouser-sponsor-1-a.jpg" style="width: 766px;" class="fr-fic fr-dib"><hr><h3 id="isPasted">EPISODE NOTES</h3>(0:55) - <a href="https://www.wevolver.com/article/inspired-by-dandelion-seeds-these-tiny-battery-free-sensor-systems-ride-the-wind" target="_blank">Dandelion Inspired Sensors</a> 🍃(11:45) - <a href="https://www.wevolver.com/article/self-propelled-endlessly-programmable-artificial-cilia" target="_blank">Microscale Robotic Cilia</a> 🦠<hr>As always, you can find these and other interesting &amp; impactful engineering articles on Wevolver.com.To learn more about this show, please visit our<a href="https://www.wevolver.com/profile/the.next.byte" target="_blank">&nbsp;shows page</a>. By following the page, you will get automatic updates by email when a new show is published. Be sure to give us a follow and review on<a href="https://podcasts.apple.com/nl/podcast/the-next-byte/id1548255861?l=en" target="_blank">&nbsp;Apple</a> podcasts,<a href="https://open.spotify.com/show/6lPPsRtegnivsRUEsQ09R7?si=IPMiah7xT_apJtPjqvXMlA" target="_blank">&nbsp;Spotify</a>, and most of your favorite podcast platforms!

This prototype sensor, pictured by Mark Stone at the University of Washington, disperses itself on the wind and harvests sunlight for energy.

In this episode, we talk about how engineers inspired by some of biology’s most miniature wonders (like dandelions' seeds and microorganisms' cilia) are using their knowledge to make major breakthroughs in biosensing, robotics, biomedical engineering, and more.

Podcast: Size Matters: Tiny Biomimicry Leads to Big Breakthroughs

In this episode, we talk about how ostriches are inspiring a new generation of bipedal robots and the innovation enabling remote endovascular surgery. As always, you can find these and other interesting &amp; impactful engineering articles on Wevolver.com.<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/e2238814-9212-4010-afb6-ac48d637140f?dark=false" class="fr-draggable" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true"></iframe><hr>This podcast is sponsored by <a href="https://www2.mouser.com/" id="isPasted" rel="nofollow" target="_blank">Mouser Electronics</a>.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1651565842197-Mouser-sponsor-1-a.jpg" style="width: 766px;" class="fr-fic fr-dib"><hr>(0:50) -&nbsp;<a href="https://www.wevolver.com/article/birdbot-a-3d-printed-bipedal-robot-offers-major-efficiency-gains-through-avian-biomimicry" target="_blank">Using Bird Biology To Make Efficient Walking Robots</a>(20:45) -&nbsp;<a href="https://www.wevolver.com/article/joystick-operated-robot-could-help-surgeons-treat-stroke-remotely" target="_blank">Joystick-operated Robot For Treating Strokes</a>Episode 68 was brought to you by Mouser Electronics, Farbod &amp; Daniel&rsquo;s favorite electronics distributor. Click <a href="https://www.mouser.com/applications/future-robotics-singularity/" target="_blank">here</a> to read the article discussing the merger of technology and humanity.<hr>About the podcast:Every day, some of the most innovative universities, companies, and individual technology developers share their knowledge on Wevolver. To ensure we can also provide this knowledge for the growing group of podcast listeners, we started a collaboration with two young engineers, Daniel Scott Mitchell &amp; Farbod Moghaddam who discuss the most interesting content in this podcast series.&nbsp;To learn more about this show, please visit the <a href="https://www.wevolver.com/profile/the.next.byte" target="_blank">shows page</a>. By following the page, you will get automatic updates by email when a new show is published.Be sure to give us a follow and review on <a href="https://podcasts.apple.com/nl/podcast/the-next-byte/id1548255861?l=en" rel="nofollow" target="_blank">Apple</a> podcasts, <a href="https://open.spotify.com/show/6lPPsRtegnivsRUEsQ09R7?si=IPMiah7xT_apJtPjqvXMlA" rel="nofollow" target="_blank">Spotify</a>, and most of your favorite podcast platforms!Take a few seconds to leave us a review. It really helps! <a href="https://apple.co/2RIsbZ2" rel="nofollow" target="_blank">https://apple.co/2RIsbZ2&nbsp;</a>if you do it and send us proof, we&rsquo;ll give you a shoutout on the show.

The prototype motorized BirdBot, seen here with legs in the locked position, uses a quarter the energy of its immediate predecessor.

In this episode, we talk about how ostriches are inspiring a new generation of bipedal robots and the innovation enabling remote endovascular surgery. 

Podcast: Bird-inspired Bipedal Robots & Robotic Surgeons

This article was discussed in our <a data-saferedirecturl="https://www.google.com/url?q=https://www.wevolver.com/profile/the.next.byte&source=gmail&ust=1651619086659000&usg=AOvVaw31M1Y-wsRw4c0h8-at-VxZ" href="https://www.wevolver.com/profile/the.next.byte" id="isPasted" 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/e2238814-9212-4010-afb6-ac48d637140f?dark=false" class="fr-draggable" data-gtm-yt-inspected-1_19="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true"></iframe>The full article will continue below.<hr>Watching a bird like an ostrich running reveals a locomotive mechanism far closer to a creature like the mighty Tyrannosaurus Rex than the human leg, and few could doubt its efficacy &mdash; leading a team at the Dynamic Locomotion Group of the Max Planck Institute for Intelligent Systems (MPI-IS) to wonder if current approaches for bipedal robot designs could benefit from being more bird.&ldquo;No current bipedal robot can run quickly, untethered, in natural environments over long distances,&rdquo; the researchers explain in a recently-published paper. &ldquo;However, these activities are commonplace for terrestrial animals. Paradoxically, animals vastly outperform current robots despite considerably slower sensing and information transfer rates.&rdquo;<h1>Inspired by, and defining, nature</h1>Before you can take inspiration from bird locomotion, however, you need to ascertain why it&rsquo;s so effective &mdash; and that&rsquo;s not necessarily an easy task. &ldquo;It&rsquo;s not the nervous system, it&rsquo;s not electrical impulses, it&rsquo;s not muscle activity,&rdquo; claims senior author Alexander Badri-Spr&ouml;witz. &quot;We hypothesized a new function of the foot-leg coupling through a network of muscles and tendons that extends across multiple joints.&ldquo;These multi-joint muscle-tendon coordinate foot folding in the swing phase. In our robot, we have implemented the coupled mechanics in the leg and foot, which enables energy-efficient and robust robot walking. Our results demonstrating this mechanism in a robot lead us to believe that similar efficiency benefits also hold true for birds.&rdquo;<iframe src="https://www.youtube.com/embed/wwH40rYJt9g?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" allowfullscreen="" class="fr-draggable" width="640" height="360" frameborder="0" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-gtm-yt-inspected-1_19="true" id="501349169"></iframe> Dubbed BirdBot, the resulting design is used to prove the team&rsquo;s hypothesis in two directions: firstly that taking inspiration from the leg of a bird can boost the performance of a bipedal robot while simultaneously boosting energy efficiency; and secondly using the resulting robot design to determine the aspects of the leg which contribute most to the efficiency of its living inspiration.Each leg of the BirdBot design uses just two actuator motors, with a traditional third replaced by a clever joint system featuring a joint based on intrinsic engaging and disengaging abilities. As the robot&rsquo;s foot touches the ground and experiences load, the joint system tenses and stiffens to support the weight; as it&rsquo;s lifted off and swung, a bi-stable snap-through joint driven by elastically-stored energy unlocks the leg into a slack configuration.<h1>Simply better</h1>The BirdBot approach comes with a host of improvements over traditional designs, its creators claim. The most immediately obvious: It&rsquo;s electronically simpler, using only two motors and with no need for on-board sensing or complicated control circuitry. Instead, the leg itself handles locking and unlocking automatically &mdash; and can even handle stabilization using a single feed-forward motor command.Its biggest enhancement: Efficiency. Compared to the Cheetah-Cub design published back in 2013, BirdBot requires around a quarter of the energy for locomotion &mdash; putting its performance within the range, its creators say, of &ldquo;an animal of equivalent weight.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ5ODY0MDM4NzU4LWJpcmRib3QzLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib" alt="A picture of the BirdBot prototype, seen next to a diagram making its major parts including knee and hip motors and the tendons which allow it to engage and disengage a clutch-like leg. Further photographs are given of the robot being tested on a treadmill with tethered guidance.">The 3D-printed BirdBot prototype operates with just two motors per leg, relying on a mechanical &quot;clutch&quot; system inspired by birds&#39; legs for the remainder of its operation.&ldquo;Previously, our robots had to work against the spring or with a motor either when standing or when pulling the leg up, to prevent the leg from colliding with the ground during leg swing. This energy input is not necessary in BirdBot&rsquo;s legs,&rdquo; Badri-Spr&ouml;witz, who also led the Cheetah-Cub team, explains.Other advantages claimed in the paper detailing BirdBot&rsquo;s design include the ability to stand upright through torque loading, with all actuators unpowered &mdash; &ldquo;reminiscent,&rdquo; say its creators, &ldquo;of a flamingo standing while sleeping&rdquo; &mdash; and of being highly scalable, with one prototype created during the work standing 1.75m (around 5.7 feet) tall and able to hold the weight of a human being.&ldquo;On the basis of our analysis and physical demonstrations,&rdquo; the team concludes, &ldquo;we suggest that BirdBot&rsquo;s leg design can become a blueprint for large legged machines.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjQ5ODY0MDUyNDkwLWJpcmRib3Q0LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib" alt="Photographs showing the small BirdBot prototype next to an unpowered large-scale 1.75m version based on the same principles. A researcher is seen placing his weight on the leg in its standing position, then stepping off to the floor and lifting the leg to its swinging position.">A large-scale version of the leg proved capable of holding the weight of an adult human &mdash; and its creators say it could be scaled up still further.That&rsquo;s not to say their work is finished, however. The current motorized BirdBot prototype, which uses off-the-shelf actuators fitted to a 3D-printed trunk and legs, has been tested on a treadmill with tethered guidance.To create a version capable of standing freely and moving in three dimensions will require further research to prevent pitching, potentially involving a revised design or a shift to hip-only actuation. While operable without sensor input, the team also suggests that an investigation into how the clutch mechanism could be used alongside direct actuation and sensory feedback control to &ldquo;merge the benefits of both systems.&rdquo;The team&rsquo;s work has been published in the journal <a href="https://www.science.org/doi/10.1126/scirobotics.abg4055" target="_blank"><cite>Science Robotics</cite></a>, with an open-access version available via author referral <a href="https://is.mpg.de/publications/bb01" target="_blank">on the MPI publication page</a>.<h1>References</h1>Alexander Badri-Spr&ouml;witz, Alborz Aghamaleki Sarvestani, Metin Sitti, and Monica A. Daley: <cite>BirdBot achieves energy-efficient gait with minimal control using avian-inspired leg clutching, Science Robotics Vol. 7 Iss. 64</cite>. DOI <a href="https://doi.org/10.1126/scirobotics.abg4055" target="_blank">10.1126/scirobotics.abg4055</a>.Alexander Badri-Spr&ouml;witz (as Alexander Spr&ouml;witz), Alexandre Tuleu, Massimo Vespignani, Mostafa Ajallooeian, Emilie Badri, and Auke Jan Ijspeert: <cite>Towards dynamic trot gait locomotion: Design, control, and experiments with Cheetah-cub, a compliant quadruped robot, The International Journal of Robotics Research Vol. 32 Iss. 8</cite>. DOI <a href="https://doi.org/10.1177/0278364913489205" target="_blank">10.1177/0278364913489205</a>.

Created by the Dynamic Locomotion Group at the Max Planck Institute for Intelligent Systems (MPI-IS), BirdBot serves two purposes: Demonstrating a more efficient bipedal robot design, and furthering our understanding of how birds' legs work.

BirdBot, a 3D-printed bipedal robot, offers major efficiency gains through avian biomimicry

The next step in machine learning, how 3D printing will change the airline industry, and why flies hold the secret to robotic flight. As always, you can find these articles and other interesting engineering content on Wevolver.com.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/f6b5e009-6f76-413b-a49b-032c4fc123db?dark=false" class="fr-draggable"></iframe><h2 data-v-1111b158="" data-v-8334d7b8="">Episode Notes</h2><div data-v-1111b158="" data-v-8334d7b8="">(0:40) <a href="https://www.wevolver.com/article/toward-a-machine-learning-model-that-can-reason-about-everyday-actions" target="_blank">The next stop in machine learning: making sense of abstract concepts</a> - Researchers from MIT, IBM, and Columbia created a machine learning model that exhibits abstract reasoning.&nbsp;(6:00) <a href="https://www.wevolver.com/article/adoption-of-additive-manufacturing-in-airline-interiors" target="_blank">How additive manufacturing can shift manufacturing methodologies in the airline industry</a> - EOS and other 3D printing companies are changing the airline industry’s manufacturing methods, starting with interiors.(12:15) <a href="https://www.wevolver.com/article/eye-of-a-fly-researchers-reveal-secrets-of-fly-vision-for-rapid-flight-control" target="_blank">Can flies hold the secret to enable enhanced robotic flight?</a> - Penn State researchers crack the code to improve robotic flight by studying the behavior of fruit flies.&nbsp;&nbsp;--About the podcast:Every day, some of the most innovative universities, companies, and individual technology developers share their knowledge on Wevolver. To ensure we can also provide this knowledge for the growing group of podcast listeners, we started a collaboration with two young engineers, Daniel Scott Mitchell &amp; Farbod Moghaddam who discuss the most interesting content in this podcast series.&nbsp;To learn more about this show, please visit the&nbsp;<a href="https://www.wevolver.com/profile/the.next.byte" target="_blank">shows page</a>. By following the page, you will get automatic updates by email when a new show is published.Be sure to give us a follow and review on&nbsp;<a href="https://podcasts.apple.com/nl/podcast/the-next-byte/id1548255861?l=en" target="_blank">Apple</a> podcasts,&nbsp;<a href="https://open.spotify.com/show/6lPPsRtegnivsRUEsQ09R7?si=IPMiah7xT_apJtPjqvXMlA" target="_blank">Spotify</a>, and most of your favorite podcast platforms!</div>

The next step in machine learning, how 3D printing will change the airline industry, and why flies hold the secret to robotic flight.

Podcast: Abstract Machine Learning, 3D Printing Airplanes, Learning Flight From Flies

Orthopaedic cast immobilisation is one of the most common ways to treat broken and fractured bones. This process involves the use of materials to encase and restrict the movement of broken bones, allowing them to heal.As technology has become more accessible, 3D Printed casts have grown in popularity. They are much lighter, more comfortable and easier to produce than traditional casts. Despite the evolution in cast production qualities, all casts share a fundamental flaw &ndash; they are single-use products.Since the job of a cast is to set body parts in a fixed position, they have to be tailor-made to the unique anatomy of the individual patients.3D printed casts are also complex in their structure, these factors eliminate the possibility of reusing casts, even if hygiene issues were non-existent.&nbsp;CREATE Education Ambassador, <a href="https://www.createeducation.com/community-partner/jack-cockle/" target="_blank">Jack Cockle</a> identified an opportunity to explore alternative strategies to make immobilisation casts more sustainable. With an aim to reduce the inevitable waste generated by their complex and tailored form and maintenance of hygiene standards. <img class="fr-fic fr-dib" src="https://images.wevolver.com/eyJidWNrZXQiOiAid2V2b2x2ZXItcHJvamVjdC1pbWFnZXMiLCAia2V5IjogImZyb2FsYS8xNjA0NDg3NDY4NDE4LUpDUzUuanBnIiwgImVkaXRzIjogeyJyZXNpemUiOiB7IndpZHRoIjogOTUwLCAiZml0IjogImNvdmVyIn19fQ==" style="width: 300px;"><h1 dir="ltr">The Process</h1>As part of one of Jack&rsquo;s final year projects whilst studying BA (Hons) Sustainable Product Design, he began by making a normal plaster cast, trialling traditional methods of the cast making to justify future design choices.Then making a basic 3D printed cast, by scanning his hand/arm using a 3D scanner and software. Exporting the scan as an STL file into <a href="https://marketplace.createeducation.com/product/fusion-360-software-training/" target="_blank">Autodesk Fusion 360</a>, which was then converted to a b-rep file, allowing Jack to model a form around the hand/arm.Next, 3D printing the cast in <a href="https://marketplace.createeducation.com/?swoof=1&post_type=product&pa_material=petg&paged=1" target="_blank">rPETG</a> on the <a href="https://marketplace.createeducation.com/product/ultimaker-s5-3d-printer/" target="_blank">Ultimaker S5</a>. This was made easier by the scale of the printer, saving time where Jack would have had to split up the model into more pieces, then glueing them together.&nbsp;To explore the scope of making casts more sustainable, Jack evaluated multiple design ideas through an iterative process. The aim was to investigate the possibility of fabricating 3D printed casts that adapt to the form of the user, rather than existing as a rigid form tailored to individual patients, thus making them more suitable for reuse.This idea came to Jack as his colleagues tried on the 3D printed cast, which almost, but didn&rsquo;t perfectly fit them due to the varied shapes of individuals&#39; limbs.Owing to Auxetic materials and structures exhibiting certain abnormal mechanical responses, thanks to the possession of negative Poisson&rsquo;s ratio response. Meaning they get thicker when stretched lengthwise and thinner when compressed. Jack began experimenting with auxetic forms in different materials such as <a href="https://marketplace.createeducation.com/product-category/filament/?swoof=1&paged=1&pa_material=tpu&really_curr_tax=812-product_cat" target="_blank">TPU</a> and Flexible Resin.<img class="fr-fic fr-dib" src="https://images.wevolver.com/eyJidWNrZXQiOiAid2V2b2x2ZXItcHJvamVjdC1pbWFnZXMiLCAia2V5IjogImZyb2FsYS8xNjA0NDg4NTU1MjYyLTMwMGRwaUR5bmFtaUNhc3QzLmpwZyIsICJlZGl0cyI6IHsicmVzaXplIjogeyJ3aWR0aCI6IDk1MCwgImZpdCI6ICJjb3ZlciJ9fX0=" style="width: 300px;"> In Rhino3D, Jack generated a series of cylindrical auxetic lattice forms, choosing the ones that required no support material (as this would be difficult to remove from such a complex structure). Jack printed them in both TPU and flexible resin to test how well each structure and material compressed under pressure.The concept was a flexible resin auxetic sleeve that fits over the arm of the patient, which is compressed by the rigid PETg shell, immobilising the limb.In theory, the reusable cast would reduce waste, cut lead times (as a stock of casts could be kept) and the longer-term cost of casts per patient (since the costs of one cast could be distributed across several patients).Recommended reading:&nbsp;<a href="https://www.wevolver.com/article/introducing-antibacterial-properties-into-additive-manufactured-parts" rel="noopener noreferrer" target="_blank">Introducing Antibacterial Properties Into Additive Manufactured Parts</a>Jack has been developing the mesh further, to become elastic resin bands that are finer, have more layers, and are preinstalled into the cast shell before being applied to the arm. <img class="fr-fic fr-dib" src="https://images.wevolver.com/eyJidWNrZXQiOiAid2V2b2x2ZXItcHJvamVjdC1pbWFnZXMiLCAia2V5IjogImZyb2FsYS8xNjA0NDg5Mzc1NzUyLTMwMGRwaUR5bmFtaUNhc3QyICgxKS5qcGciLCAiZWRpdHMiOiB7InJlc2l6ZSI6IHsid2lkdGgiOiA5NTAsICJmaXQiOiAiY292ZXIifX19" style="width: 300px;"><hr><h2 dir="ltr">Do you want to CREATE the Future of Education?</h2>Industry is adopting additive manufacturing at an exponential rate, it is critical to be equipped with the skills needed in employment.&nbsp;It is imperative that individuals experience these ground-breaking technologies today, to futureproof UK manufacturing in a globally competitive marketplace and address the many global issues we face.CREATE Education are expert providers across the UK and Ireland, specialising in developing 3D technologies in education, to enable learners and empower educators.&nbsp;Get in touch with our education specialists today on 01257 276 116 or email us at&nbsp;<a href="mailto:enquiries@createeducation.com" target="_blank">enquiries@createeducation.com</a>.

Further harnessing 3D printing technology to promote sustainability within the medical industry

As technology has become more accessible, 3D Printed casts have grown in popularity,  owing to several benefits. However, all casts share a fundamental flaw - they are single-use products

3D Printing Sustainable Casts

I know what you are thinking: cellular materials and lightweighting? Who made this guy a Professor? I hear you. While my students and I have spent a lot of time the past four years studying cellular materials, it has been in the context of energy absorption, honeycomb panel design, capillary action, and thermal management, and not with the intent to lightweight (is it now ok to use it as a verb?) a structure. However, when nTopology approached me with a request to contribute to a series of talks on lightweighting, I wondered if this was a good time to enter the dark dungeon and chat with the trolls. The result of my explorations is this blog post, and the accompanying webinar, that I hope will spark some ideas, if not justify my hiring.Traditional approaches to lightweighting involve material selection, consolidation, and topology optimization (Figure 1). Design solutions are of particular importance when working with higher density metals where composition is selected for reasons such as high temperature performance or corrosion resistance, and the door to lower-density materials is closed. Cellular materials such as lattices and foams are typically not thought of as leading design candidates for lightweighting, and skepticism in this area is well founded. There are several reasons for this, most fundamentally perhaps being the point that the very requirement of structure to have cellularity is in itself a limiting constraint from a design optimization standpoint. Nonetheless, I would like to stick my neck out and examine if this always must be the case.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjAxMjI1MDc0NjI1LWZpZ3VyZS0xLWRiLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=">Figure 1: Traditional approaches to lightweighting include (a) material selection, (b) consolidation, and (c) topology optimization [Photo credits – (a): CES EduPack 2018, Granta Design Ltd., (b) and (c): nTopology]&nbsp;The first argument for why we need to consider cellular materials in the context of lightweighting, and one I will focus in this blog post, is the argument from nature. We do find cellular structures in biological structure (Figure 2), such as insect nests, turtle shells, bone, and sea urchin spines, where mass minimization is always an inherent requirement. In some cases, such as the beaks and bones of birds, lightweighting is critical. As the songwriter J.J. Cale put it, “Travelin’ light is the only way to fly.” Fortunately he gives us no details about how this is to be accomplished, which is why engineers like you and me still have jobs in this world, and care enough to write and read (?) blog posts.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjAxMjI1MDk3NjI4LWZpZ3VyZS0yLWRiLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=">Figure 2: Natural structures where minimizing weight is of importance, and also exhibit cellular material design: (a) Venation of a water lily leaf, (b) wasp nest, (c) trabecular bone [Photo Credits: Wikimedia Commons (a) Laitr Keiows; (c) Neon]&nbsp;This apparent paradox can be resolved by making the argument that there are (at least) three performance objectives, which when sought, strengthen the candidacy of cellular materials for lightweighting: surface and volume infilling, multi-functionality, and damage tolerance. We find these demonstrated in natural structure, but also in engineering applications that embody cellular materials for these reasons, including honeycomb core commonly used in panels. These insights can be leveraged to inform engineering design of lightweight structures, and implemented by leveraging a framework for cellular material design that consists of four concepts: discretization, periodicity, gradients, and hierarchy. These concepts lend themselves very well to study in the context of nTopology’s equation-based implicit modeling platform (small p intended). One example of this is work done by one of my students using nTopology to create different geometries to study the effect of aperiodicity (Figure 3).&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjAxMjI1MTIyMDAyLWZpZ3VyZS0zLWRiLnBuZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=">Figure 3: Use of nTopology to develop cellular material designs with varying degrees of aperiodicity [Photo Credits: Daniel Anderson, 3DX Research, ASU]&nbsp;Lest I be accused of “having a hammer and looking for a nail”, which while fair, is not the entire story, I would like to end by clarifying that cellular materials merely represent an alternative for lightweighting when the performance objectives mentioned previously are also being sought. However, I will go a step further and speculate that cellular material design is a critical element at the frontier of lightweighting since it helps us enable true multi-functional, material-and-structure co-optimization at a range of scales. Of course at this point, cellular design and other techniques blend into each other, and the boundaries between formal approaches to lightweighting start to break down. This is my second argument for why we need to consider cellular materials for lightweighting: they tie everything together. How am I so sure? Because life, uh, has found a way.&nbsp;<hr><h3>References</h3><ol><li>Harris, “Five Techniques for Lightweighting: Doing More With Less,” January 2020, <a href="https://www.techbriefs.com/component/content/article/tb/pub/features/articles/35824" target="_blank">https://www.techbriefs.com/component/content/article/tb/pub/features/articles/35824</a></li><li>du Plessis, C. Broeckhoven, I. Yadroitsava, I. Yadriotsev, C. Hands, R. Kunju, D. Bhate, “Beautiful and Functional: A Review of Biomimetic Design in Additive Manufacturing,” Additive Manufacturing, Volume 27, pages 408-427, May 2019</li><li>Bhate, C. Penick, L. Ferry, C. Lee, “Classification and Selection of Cellular Materials in Mechanical Design: Engineering and Biomimetic Approaches,” Invited paper, Special Issue on Advances in Biologically Inspired Design, MDPI Designs, 3(1), 19, 2019</li><li>J. Cale, “Travelin’ Light”, Troubadour, Shelter Records, 1976</li><li>Malcolm, “Jurassic Park,” Universal Studios, 1993</li></ol><hr>This article was first published on the <a href="https://ntopology.com/blog/2020/08/21/lightweighting-with-cellular-materials-insights-from-nature/" rel="noopener noreferrer" target="_blank">nTopology blog.</a>

Can cellular materials serve as a design solution for achieving lightweighting of engineering structures? Let’s listen to what nature has to say.

Lightweighting with Cellular Materials: Insights from Nature

<h2>Akira Science AB, a start-up based in Stockholm, is betting on the combination of two revolutionary disciplines: tissue engineering and 3D printing.&nbsp;</h2>These two disciplines used to belong to two different stories that are now deeply interconnected. During the last fifty years scientists and surgeons have combined the concepts of life sciences, biology and biocompatible materials to construct functional tissues and open the way to innovative and less invasive techniques respect to traditional surgical transplants. They have been looking for new materials to substitute classical treatments to improve medical treatments where autograph or allograph of explanted tissues are required due to disease or trauma. In parallel to this story, 3D printing technologies also known as Additive Manufacturing (AM) were born in the 1980s and initially intended to quickly produce prototypes within industrial applications. When 3D printing technologies later met tissue engineering, a powerful combination consolidated to create structures with controlled geometry and high rate of reproducibility. Tissue engineers have been seeking for structures &ndash; scaffolds&nbsp;&ndash; that can provide structural and mechanical support to a damaged tissue while promoting its regeneration and allowing nutrients&rsquo; supply to the cells.The 3D printing market has been growing fast during the last decade releasing innovative technologies and materials, especially for the medical sector. 3D printing is transforming the way we manufacture objects from a centralized to a decentralized, customized production onsite.Akira Science is projected to have an active role in these future landscapes of smart and innovative manufacturing technologies applied to degradable materials for medical applications. The business potential arises from the ever-increasing need of patient-specific medical devices and of timely laboratory biological studies to test drugs and new clinical strategies - never so evident like in this pandemic period.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1590050859860-1590050859859.png" style="width: 655px;" class="fr-fic fr-dib">A cutting-edge new material and a smart scaffold design are the complementary and revolutionary points of force of Akira&rsquo;s strategy. The newly developed polymer (AKIMed-c12) has exceptional thermal stability, ensuring control of the material properties while printing, presenting a faster degradation time in the body environment than the current utilized materials (from 3-5 years to 9-10 months). Although newly formulated, AKIMed-c12 is made starting from well-established building blocks for the synthesis of approved biomedical materials, ensuring biocompatibility and non-toxicity in the physiological environment. While the printed scaffolds are not hard as the current available ones, but soft and pliable proving comfort to the patient (AKIMed-c12: 3D printed scaffolds).<iframe width="640" height="360" src="https://www.youtube.com/embed/GdgRqw2ZHjw?&wmode=opaque" frameborder="0" allowfullscreen="" class="fr-draggable"></iframe> The new material will be the workhorse for the 3D printing of degradable medical devices, while the smart design opens the way to new applications in tissue regeneration that were not possible until today utilizing the materials available on the market. Akira team is confident that such a combination has the potential to expand the scope of degradable 3D printed scaffolds from hard, for example bone, to soft tissue regeneration, such as breast reconstruction after mastectomy.Akira Science is providing both filaments for 3D printing and scaffolds with an architecture that satisfies customers&rsquo; need. Researchers and clinicians can buy the filament (AKIMed-c12: filament) and print the desired shape in their own facilities or can decide to ask Akira for printing their customized devices. Akira also provides support and consulting to collaborators and customers with material selection, design and simulation of the mechanical behavior of the desired scaffolds.The company continues to invest in open innovation through a continuous dialogue with customers and by setting new strategies to map future needs in tissue engineering and 3D printing opportunities.<hr>&Aacute;lvaro Morales and Tiziana Fuoco (AKIRA Science AB)

“The nexus between two revolutionary disciplines is inspiring us towards a future improved society”

Tissue Engineering and 3D Printing: Two Revolutionary Disciplines Now Fused Into One

The next generation of Harvard’s Ambulatory Microrobot (HAMR) can walk on land, swim on the surface of water, and walk underwater, opening up new environments for this little bot to explore.  (Credit: Yufeng Chen, Neel Doshi, and Benjamin Goldberg/Harvard University)

‘HAMR’ can walk on land, swim, and walk underwater

Next-generation robotic cockroach can explore underwater environments

Robots perform many tasks that humans can&rsquo;t or don&#39;t want to perform, getting around on intricately designed wheels and limbs. If they tip over, however, they are rendered almost useless. A team of University of Illinois mechanical engineers and entomologists are looking to click beetles, who can right themselves without the use of their legs, to solve this robotics challenge.The researchers presented their findings at Living Machines 2017: The 6th International Conference on Biomimetic and Biohybrid Systems at Stanford University, and later won second place in a student and faculty research competition at the international BIOMinnovate Challenge, in Paris, France &ndash; a research expo that showcases biologically-inspired design in engineering, medicine and architecture.<iframe src="https://www.youtube.com/embed/9ozz2jRfBUk?&wmode=opaque" allowfullscreen="" class="fr-draggable" style="width: 766px; height: 406px;" frameborder="0"></iframe> &ldquo;This idea came to life when a group of insect physiology students decided to take a closer look at what makes click beetles jump as part of a class project,&rdquo; said <a href="https://www.life.illinois.edu/entomology/index.html" target="_blank">department of entomology</a> research scientist and study co-author <a href="https://www.life.illinois.edu/entomology/faculty/alleyne.html" target="_blank">Marianne Alleyne.</a>The beetles have a unique hinge-like mechanism between their heads and abdomens that makes a clicking sound when initiated and allows them to flip into the air and back onto their feet when they are knocked over, Alleyne said.&ldquo;Very little research had been performed on these beetles, and I thought this legless jumping mechanism would be a perfect candidate for further exploration in the field of bioinspiration,&rdquo; said Alleyne, who teaches a bioinspiration design course with <a href="https://mechanical.illinois.edu/" target="_blank">mechanical science and engineering</a> professor, co-author and lead investigator <a href="https://mechanical.illinois.edu/directory/faculty/awissa" target="_blank">Aimy Wissa</a>.The researchers looked at several species of click beetles, ranging in size from a few just few millimeters to several centimeters in length.&ldquo;Each insect goes through an assembly line of analyses that involve basic characterization, high-speed filming to observe the jump and measurements in the <a href="https://publish.illinois.edu/tribology/" target="_blank">Materials Tribiology Lab</a> with co-author and mechanical science and engineering professor <a href="http://mechanical.illinois.edu/directory/profile/acd" target="_blank">Alison Dunn</a>, to determine how much force it takes to overcome the friction of the hinge within an individual beetles jumping mechanism,&rdquo; Wissa said. &ldquo;We observe, model and validate each stage of the jump with the hopes that we can later integrate them into a self-righting robot.&rdquo;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1568998642025-118939.jpg" style="width: 766px;" class="fr-fic fr-dib">The University of Illinois click beetle robotics team. Front row, from left: Professor Aimy Wissa, Aidan Garrett, Luis Urrutia, Ophelia Bolmin and professor Alison Dunn. Back row, from left: Isandro Malik, Xander Hazel, Robert Chapa, Harmen Alleyne, Chengfang Duan and research scientist Marianne Alleyne. Garrett, Malik and H. Alleyne are University of Illinois Laboratory High School students. Photo by L. Brian StaufferThe group has already built several prototypes of a hinge-like, spring-loaded device that will eventually be incorporated into a robot, the researchers said.&ldquo;This study is a two-way street &ndash; engineers are informing the biologists and vice versa,&rdquo; Wissa said. &ldquo;We look forward to seeing where this research will take us and are very proud of the attention it received at the BIOMinnovate Challenge expo.&rdquo;

Click beetles can jump without the aid of their limbs when they are tipped onto their backsides. A team of University of Illinois researchers are examining this mechanism to engineer self-righting robots.  Photo by L. Brian Stauffer

Robots perform many tasks that humans can’t or don't want to perform, getting around on intricately designed wheels and limbs. If they tip over, however, they are rendered almost useless.

Click beetles inspire design of self-righting robots

Compression therapy is a standard form of treatment for patients who suffer from venous ulcers and other conditions in which veins struggle to return blood from the lower extremities. Compression stockings and bandages, wrapped tightly around the affected limb, can help to stimulate blood flow. But there is currently no clear way to gauge whether a bandage is applying an optimal pressure for a given condition.Now engineers at MIT have developed pressure-sensing photonic fibers that they have woven into a typical compression bandage. As the bandage is stretched, the fibers change color. Using a color chart, a caregiver can stretch a bandage until it matches the color for a desired pressure, before, say, wrapping it around a patient&rsquo;s leg.The photonic fibers can then serve as a continuous pressure sensor &mdash; if their color changes, caregivers or patients can use the color chart to determine whether and to what degree the bandage needs loosening or tightening.&ldquo;Getting the pressure right is critical in treating many medical conditions including venous ulcers, which affect several hundred thousand patients in the U.S. each year,&rdquo; says Mathias Kolle, assistant professor of mechanical engineering at MIT. &ldquo;These fibers can provide information about the pressure that the bandage exerts. We can design them so that for a specific desired pressure, the fibers reflect an easily distinguished color.&rdquo;Kolle and his colleagues have published their results in the journal Advanced Healthcare Materials. Co-authors from MIT include first author Joseph Sandt, Marie Moudio, and Christian Argenti, along with J. Kenji Clark of the Univeristy of Tokyo, James Hardin of the United States Air Force Research Laboratory, Matthew Carty of Brigham and Women&rsquo;s Hospital-Harvard Medical School, and Jennifer Lewis of Harvard University.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1568994301001-single-fiber-stretch.gif" style="width: 766px;" class="fr-fic fr-dib">Natural inspirationThe color of the photonic fibers arises not from any intrinsic pigmentation, but from their carefully designed structural configuration. Each fiber is about 10 times the diameter of a human hair. The researchers fabricated the fiber from ultrathin layers of transparent rubber materials, which they rolled up to create a jelly-roll-type structure. Each layer within the roll is only a few hundred nanometers thick.In this rolled-up configuration, light reflects off each interface between individual layers. With enough layers of consistent thickness, these reflections interact to strengthen some colors in the visible spectrum, for instance red, while diminishing the brightness of other colors. This makes the fiber appear a certain color, depending on the thickness of the layers within the fiber.&ldquo;Structural color is really neat, because you can get brighter, stronger colors than with inks or dyes just by using particular arrangements of transparent materials,&rdquo; Sandt says. &ldquo;These colors persist as long as the structure is maintained.&rdquo;The fibers&rsquo; design relies upon an optical phenomenon known as &ldquo;interference,&rdquo; in which light, reflected from a periodic stack of thin, transparent layers, can produce vibrant colors that depend on the stack&rsquo;s geometric parameters and material composition. Optical interference is what produces colorful swirls in oily puddles and soap bubbles. It&rsquo;s also what gives peacocks and butterflies their dazzling, shifting shades, as their feathers and wings are made from similarly periodic structures.&ldquo;My interest has always been in taking interesting structural elements that lie at the origin of nature&rsquo;s most dazzling light manipulation strategies, to try recreating and employing them in useful applications,&rdquo; Kolle says.<img src="blob:https://www.wevolver.com/6c22c5d1-56bb-4ed0-a5ce-9b2933c079ca" style="width: 766px;" class="fr-fic fr-dib">A multilayered approachThe team&rsquo;s approach combines known optical design concepts with soft materials, to create dynamic photonic materials.While a postdoc at Harvard in the group of Professor Joanna Aizenberg, Kolle was inspired by the work of Pete Vukusic, professor of biophotonics at the University of Exeter in the U.K., on&nbsp;Margaritaria nobilis,&nbsp;a tropical plant that produces extremely shiny blue berries. The fruits&rsquo; skin is made up of cells with a periodic cellulose structure, through which light can reflect to give the fruit its signature metallic blue color.Together, Kolle and Vukusic sought ways to translate the fruit&rsquo;s photonic architecture into a useful synthetic material. Ultimately, they fashioned multilayered fibers from stretchable materials, and assumed that stretching the fibers would change the individual layers&rsquo; thicknesses, enabling them to tune the fibers&rsquo; color. The results of these first efforts were published in&nbsp;Advanced Materials in 2013.When Kolle joined the MIT faculty in the same year, he and his group, including Sandt, improved on the photonic fiber&rsquo;s design and fabrication. In their current form, the fibers are made from layers of commonly used and widely available transparent rubbers, wrapped around highly stretchable fiber cores. Sandt fabricated each layer using spin-coating, a technique in which a rubber, dissolved into solution, is poured onto a spinning wheel. Excess material is flung off the wheel, leaving a thin, uniform coating, the thickness of which can be determined by the wheel&rsquo;s speed.For fiber fabrication, Sandt formed these two layers on top of a water-soluble film on a silicon wafer. He then submerged the wafer, with all three layers, in water to dissolve the water-soluble layer, leaving the two rubbery layers floating on the water&rsquo;s surface. Finally, he carefully rolled the two transparent layers around a black rubber fiber, to produce the final colorful photonic fiber.&shy;&shy;Reflecting pressureThe team can tune the thickness of the fibers&rsquo; layers to produce any desired color tuning, using standard optical modeling approaches customized for their fiber design.&ldquo;If you want a fiber to go from yellow to green, or blue, we can say, &lsquo;This is how we have to lay out the fiber to give us this kind of [color] trajectory,&rsquo;&rdquo; Kolle says. &ldquo;This is powerful because you might want to have something that reflects red to show a dangerously high strain, or green for &lsquo;ok.&rsquo; We have that capacity.&rdquo;The team fabricated color-changing fibers with a tailored, strain-dependent color variation using the theoretical model, and then stitched them along the length of a conventional compression bandage, which they previously characterized to determine the pressure that the bandage generates when it&rsquo;s stretched by a certain amount.The team used the relationship between bandage stretch and pressure, and the correlation between fiber color and strain, to draw up a color chart, matching a fiber&rsquo;s color (produced by a certain amount of stretching) to the pressure that is generated by the bandage.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1568995401582-MIT-Bandage-Pressure-02.jpg" style="width: 766px;" class="fr-fic fr-dib">As the bandage is stretched, the fibers change color. Courtesy of the researchersTo test the bandage&rsquo;s effectiveness, Sandt and Moudio enlisted over a dozen student volunteers, who worked in pairs to apply three different compression bandages to each other&rsquo;s legs: a plain bandage, a bandage threaded with photonic fibers, and a commercially-available bandage printed with rectangular patterns. This bandage is designed so that when it is applying an optimal pressure, users should see that the rectangles become squares.Overall, the bandage woven with photonic fibers gave the clearest pressure feedback. Students were able to interpret the color of the fibers, and based on the color chart, apply a corresponding optimal pressure more accurately than either of the other bandages.The researchers are now looking for ways to scale up the fiber fabrication process. Currently, they are able to make fibers that are several inches long. Ideally, they would like to produce meters or even kilometers of such fibers at a time.&ldquo;Currently, the fibers are costly, mostly because of the labor that goes into making them,&rdquo; Kolle says. &ldquo;The materials themselves are not worth much. If we could reel out kilometers of these fibers with relatively little work, then they would be dirt cheap.&rdquo;Then, such fibers could be threaded into bandages, along with textiles such as athletic apparel and shoes as color indicators for, say, muscle strain during workouts. Kolle envisions that they may also be used as remotely readable strain gauges for infrastructure and machinery.&ldquo;Of course, they could also be a scientific tool that could be used in a broader context, which we want to explore,&rdquo; Kolle says.

Engineers at MIT have developed pressure-sensing photonic fibers that they have woven into a typical compression bandage  Courtesy of the researchers

Bandage is threaded with photonic fibers that change color to signal pressure level.

Engineers design color-changing compression bandage

The work blurs the boundary between materials and robots. In the self-propelled devices, the material itself makes the machine function. "Our examples show that we can use structured materials that deform in response to environmental cues, to control and propel robots," says Daraio, professor of mechanical engineering and applied physics in Caltech's Division of Engineering and Applied Science, and corresponding author of a paper unveiling the robots that appears in the Proceedings of the National Academy of Sciences&nbsp;on May 15.The new propulsion system relies on strips of a flexible polymer that is curled when cold and stretches out when warm. The polymer is positioned to activate a switch inside the robot's body, that is in turn attached to a paddle that rows it forward like a rowboat.The switch is made from a bistable element, which is a component that can be stable in two distinct geometries. In this case, it is built from strips of an elastic material that, when pushed on by the polymer, snaps from one position to another.<iframe src="https://www.youtube.com/embed/tBxb1A6boTI?&amp;wmode=opaque" allowfullscreen="" class="fr-draggable" style="width: 767px; height: 439px;" frameborder="0"></iframe>When the cold robot is placed in warm water, the polymer stretches out, activates the switch, and the resulting sudden release of energy paddles the robot forward. The polymer strips can also be "tuned" to give specific responses at different times: that is, a thicker strip will take longer to warm up, stretch out, and ultimately activate its paddle than a thinner strip. This tunability allows the team to design robots capable of turning and moving at different speeds.The research builds on previous work by Daraio and Dennis Kochmann, professor of aerospace at Caltech. They used chains of <a href="http://www.caltech.edu/news/utility-instability-51629" target="_blank">bistable elements to transmit signals and build computer-like logic gates</a>.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1564499883153-Screenshot_2019-07-30+Harnessing+bistability+for+directional+propulsion+of+soft%2C+untethered+robots+-+5698+full+pdf%281%29.png" style="width: 766px;" class="fr-fic fr-dib">In the latest iteration of the design, Daraio's team and collaborators were able to link up the polymer elements and switches in such a way to make a four-paddled robot propel itself forward, drop off a small payload (in this case, a token with a Caltech seal emblazoned on it), and then paddle backward.&nbsp;"Combining simple motions together, we were able to embed programming into the material to carry out a sequence of complex behaviors," says Caltech postdoctoral scholar Osama R. Bilal, co-first author of the PNASpaper. In the future, more functionalities and responsivities can be added, for example using polymers that respond to other environmental cues, like pH or salinity. Future versions of the robots could contain chemical spills or, on a smaller scale, deliver drugs, the researchers say.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1564499825448-1.jpg" style="width: 766px;" class="fr-fic fr-dib">Currently, when the bistable elements snap and release their energy, they must be manually reset in order to work again. Next, the team plans to explore ways to redesign the bistable elements so that they are self-resetting when water temperature shifts again—making them potentially capable of swimming on indefinitely, so long as water temperature keeps fluctuating.The PNAS&nbsp;paper is titled <a href="http://resolver.caltech.edu/CaltechAUTHORS:20180515-101708023" target="_blank">"Harnessing bistability for directional propulsion of soft, untethered robots."</a> Daraio and Bilal collaborated with Tian Chen and Kristina Shea from ETH in Zurich. This research was supported by the Army Research Office and an ETH postdoctoral fellowship to Bilal.

 An artist's rendering of the new design for a robot that uses material deformation to propel itself through water. 

Engineers have developed robots capable of self-propulsion without using any motors, servos, or power supply. Instead, these first-of-their-kind devices paddle through water as the material they are constructed from deforms with temperature changes.

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