Media note: Video of the robots working together can be found and downloaded here .
ITHACA, N.Y. - Cornell University physics researchers have made robots that for the first time can sense the temperature of their surroundings and react together to change it.
“Little things can have a large impact,” said Itai Cohen , a leader in developing microscopic robots and a corresponding author on the study.
This is the first example of microscopic robots that can alter their physical environment, pumping liquid from hot regions to cold regions or vice versa. Three key capabilities – environmental sensing, fluid manipulation through artificial cilia and communication among microchips – create a feedback loop inspired by systems in nature that could be used in future medical or agricultural applications.
These robots combine previous robots’ skill sets. In recent studies, Cohen and his lab have developed robots a hair’s-breadth in diameter that walk autonomously , sense their environment , make images and measurements , and communicate with each other.
“We’re building out the repertoire of things these robots can do,” Cohen said. “The idea here is, how do we get them to work together to achieve big manipulations of their environment, and this is a first step.”
“Microscopic Robots that Sense and Reshape Their Environment” published in Nature Electronics on Sept. 23.
The robot “cilia” are inspired by the fluid-pumping principle of natural cilia, postdoctoral researcher and co-first author Jinsong Zhang said. But rather than directly replicating their structure, the researchers designed a more efficient two-hinge architecture that can be readily programmed by electronic signals. Sequential movement of the two hinges produces a nonreciprocal, paddle-like motion that drives the surrounding liquid.
One paddle isn’t enough to make a difference, so many need to work together. The team set 54 hinged cilia in an array equipped with two temperature sensing circuits, a leader and a follower, which communicate with each other and synchronize the cilia in the array to pump together in response to the temperature.
“These circuits essentially tell the cilia array which hinge should pump when,” Cohen said. “If the temperature is above a certain point, then it says pump in the forward direction. If it’s a lower temperature, it says pump in the reverse direction.”
In future iterations of the concept, robots could respond to factors like light or pH level, setting off chemical reactions or mechanical motions, Cohen said. Instead of being set in a static array, the interacting robots could walk independently, programmed to react in a specific way to certain environmental cues.
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Nature Electronics