Although we have heard of all kinds of “micro-robots” before, scientists have developed a new type of micro-electronic robot, which they claim is the world’s smallest micro-robot. What’s more, it moves by firing double-injection bubbles. The device uses a propulsion system first conceived nearly a decade ago and was developed by an international team led by Professor Oliver G. Schmidt of the University of Technology in Chemnitz, Germany.
The flat miniature robot is 0.8 mm long, 0.8 mm wide and 0.14 mm high and is wirelessly operated by an external transmitter. When an electrical signal from the transmitter is received, the sensing coil in the center of the robot heats one of the two coiled polymer tubes that run vertically along both sides of the top of the robot. The two tubes are constantly inhaling hydrogen peroxide/aqueous solution, in which the robot is immersed. A small amount of platinum in each tube causes a catalytic reaction that produces oxygen bubbles that are discharged from the back end of the tube. The purpose of this setup is to generate thrust.
However, by heating one of the tubes to varying degrees, the degree of catalytic reaction in the tube can be temporarily increased (and thus increases the amount of bubbles produced). As a result, the robot can guide the robot in aqueous solution by remote control. “The way we first constructed this micro-robot was that if it didn’t apply any heat at all, it would swim in circles, ” Schmidt explains. “If some heat is applied, the turn will be compensated and the micro-robot will move upstream in a straight line. If more heat is applied, the micro-robot will turn in the other direction. “
The scientists also created a robotic arm for the device, which is in the form of a actuator made up of thermal polymers. As the heat increases or decreases, the appendages turn on or off, allowing it to catch tiny objects. In addition, the robot can be equipped with a miniature LED light source.
However, before micro-robots can be used in applications such as targetdelivery drugs in humans, they need to be modified to run in “fuels” that are more biocompatible than hydrogen peroxide. The development of this capability represents the next phase of research.
A recent paper on the study was published in the journal Nature Electronics.