It may measure just 15 millimetres in length, but this soft-bodied robot can mimic the rippling movement of a caterpillar.
The tiny caterpillar’s body is made from a light-sensitive rubbery material, which harvests energy from green light and is controlled by a laser beam.
Using these forms of light, the robotic bug can wriggle forwards on a flat surface, as well as scale slopes, squeeze through tight gaps and even carry small loads.
For decades engineers have been trying to build robots mimicking different modes of locomotion found in nature, but most of these bots had rigid skeletons and joints driven by electric or pneumatic actuators.
It has been a challenge for engineers to create robots with soft bodies like earth worms or caterpillars, and an even larger challenge to make them small, due to difficulties in power management and remote control.
But researchers at the Faculty of Physics at the University of Warsaw have managed it, to create the caterpillar bot, which sits easily on a fingertip. They described their invention in the journal Advanced Optical Materials.
They used smart materials called Liquid Crystalline Elastomers (LCEs) that can change shape when exposed to light delivered by a spatially modulated laser beam.
The experts arranged these soft materials in a stripy pattern of 3D forms, so light-induced distortion, or movement, could occur without the need for tiny actuators hidden inside its body.
By controlling the "deformation pattern" or the way the material is distorted when it absorbs light, the researchers, joined by experts from LESN in Italy and the University of Cambridge, can make the bot move like a real caterpillar. They also showed the robot can push objects 10 times its own mass, and on challenging terrains.
Piotr Wasylczyk head of the Photonic Nanostructure Facility at the University of Warsaw, said: “Designing soft robots calls for a completely new paradigm in their mechanics, power supply and control.
"We are only beginning to learn from nature and shift our design approaches towards these that emerged in natural evolution."
This article was originally published by WIRED UK
