hTetro Cleaning robots

A shape shifting cleaning robot that can change formation to accomplish the task at hand.

Singapore University of Technology and Design


The robot is able to transform itself into any of the onesided tetrominoes (a geometric shape composed of four squares, connected orthogonally)in relation to the obstacles encountered, thereby maximizing the cleaned area.


The hTromo robot comprises three squares, and two (LL) hinged points, to facilitate transformation. Block 1 contains the requisite components for movement, block 2 the electronic peripherals, and blocks 3 the cleaning components and functionality. A single robot measures 140 x 140 x 75 mm, with 4mm thick honeycomb walls formed from PLA for minimum tensile strength. The device houses six DC motors, with four mounted on block one and controlled fundamental mobility.

Caster wheels were attached to blocks 2 and 3 to maintain the position of the blocks. Block 3 also houses a tailor-made vacum module for cleaning functionality and the collection of dirt. The suction chamber and duct were specifically created to minimize loss of suction and dust spillage during operation. For the creation of the three available one-sided Tromino shapes, the robot houses two smart servos that sit on hinged points.


  • Fully autonomous operation
  • Multiple shape shifting options
  • Uses Raspberry Pi 3 for processing
  • Uses Omni Wheels (4 per unit) for movement


Wevolver 2023