Written by: Melinda Li
Edited by: Abigail Li
A Cornell-led team of researchers have recently created microscopic robots that can be controlled with electronic signals and “walk” using four legs. Their paper, published in Nature on August 26th, describes these microrobots which are about the size of paramecium — even smaller than a cross-section of a single human hair (1). Each bot includes a basic circuit made from silicon photovoltaics, which essentially converts light into electricity, and four electrochemical actuators that function as the legs (2).
As simple as they first appear, creating these robot legs actually proved to be a huge challenge for the team. “People have become very good at shrinking computer chips to microscopic dimensions. The problem was that there weren’t any legs that would work at that scale that could connect to these microchips” says Itai Cohen, one of lead researchers of the team. (3)
The legs were inspired by origami, the Japanese art of paper folding. All components of the robot begin in 2D, then the front and back legs fold up underneath the robot. When low voltages are applied to the legs, they bend and drive the robot forward. “Controlling a tiny robot is maybe as close as you can come to shrinking yourself down,” says Professor Marc Miskin, lead author of the study. Researchers control the robots with laser pulses at several photovoltaic units, each of which controls a separate set of legs. The robot “walks” by alternating the laser pulses between the front and back photovoltaics. (2)
These robots can be easily mass produced – it would take less than a week to make a million robots with this method. Researchers are currently looking at ways to increase the functionality of the robots with more complex hardware and computation. The implications of this discovery are very exciting, and these robots could soon appear in medical settings as microsurgery devices. In the future, they could be injected locally to suture blood vessels or destroy targets such as tumor cells and bacteria.
1. Miskin MZ, Cortese AJ, Dorsey K, Esposito EP, Reynolds MF, Liu Q, et al. Electronically integrated, mass-manufactured, microscopic robots. Nature. 2020 Aug;584(7822):557–61.
2. Nutt D. Laser jolts microscopic electronic robots into motion [Internet]. Cornell Chronicle. 2020 [cited 2020 Oct 14]. Available from: https://news.cornell.edu/stories/2020/08/laser-jolts-microscopic-electronic-robots-motion
3. The robot smaller than the width of a hair. BBC News [Internet]. [cited 2020 Oct 14]; Available from: https://www.bbc.com/news/av/technology-54327412
[Image] Miskin MZ, Cortese AJ, Dorsey K, Esposito EP, Reynolds MF, Liu Q, et al. Electronically integrated, mass-manufactured, microscopic robots. Nature. 2020 Aug;584(7822):557–61.