The EuMoBot Soft Robot Utilizes Euglenoid Movement

You may remember from your middle school biology classes that many microorganisms, such as eukaryotes, move around through fluid using whip-like flagella tails. But, if that fluid is particularly viscous they’re unable to move efficiently. A eukaryote subset called Euglena have evolved to compensate for that by altering the form of their bodies in a sequence that moves them along called “euglenoid movement.” EuMoBot is a much larger soft robot that replicates that movement.

Euglenoid movement is characterized by an actual change in body shape, as opposed to the kind of squirming movement utilized by snakes and worms. Euglena modify the shape of their bodies to squeeze through viscous fluid, and EuMoBot works in the same way. EuMoBot is a soft robot shaped like a cylindrical accordion, and is smaller than a stack of dimes. It’s made of a flexible, stretchy elastomer that changes shape when fluid is pumped into internal chambers.

The entire body, including the chambers, is fabricated in a 3D-printed mold. By controlling the flow of fluid into those “hyper-elastic bellows” (HEB), the creators of EuMoBot were able to direct the robot’s locomotion through a solution of methyl cellulose in water. As it moves along, its body is distorted into a series of different shapes that allow it to squeeze through the highly-viscous solution. Like many other biologically-inspired robots, EuMoBot is just a prototype to experiment with an unusual form of movement, but it does have some potential for working in constricted spaces.