Autonomous robots have been known since Terminator, Blade Runner or other science fiction blockbusters and artificial intelligence has become more and more indispensable. Today we use more and more small helpers which do tasks for us, be it drones or robots that explore dangerous and hostile areas for us humans.

Now a research team from Cornell University led by Marc Miskin has developed microrobots that can work autonomously. These microhelpers only need light as an energy source, because they have a solar drive, can crawl and are only 70 micrometers in size and can be produced in millions. The scientists report that they can produce an army of small millions of microrobots from a small silicon wafer in a multi-step process. Individually these mini helpers would not be able to do anything, but in the swarm they would be able to solve complex tasks.

Each of these microrobots is 70 micrometers and with that thinner than a human hair and small enough to be used for medical purposes. The researchers tested some of these microbots and they survived an injection into a body and would still be intact and functional. The microbots consist of a thin glass frame, which in turn carries a thin silicon layer with etched circuits and two to four solar cells each. The body of the little helper serves the bots as a brain and is also the drive unit. With the help of silicon photovoltaics the robots can be supplied with electricity and can be controlled.

These silicon microbots can move with four legs, each consisting of bimetal strips made of nanometer-thin platinum and titanium. These 100 atom layer thin legs would be extremely stable due to this material mixture and each of the legs could carry 8000 times its own weight. The crawling of these little helpers is a designed art in itself, because whenever the bot gets electricity from the solar cell, the platinum expands on the nanopinches, while the titanium remains solid, which results in the leg bending. When the power supply is cut, the little leg made of bimetal stripes becomes straight again. For this purpose, a new class of actuators has been developed with very low energy requirements and very high load-bearing capacity. Therefore, only 200 millivolts signals would be sufficient for the movement of the Bots.

The manufacture of these microrobots also represents a new class in the production of cell-sized robots. The process takes advantage of the technology developed by the semiconductor industry to produce the bots in masses that carry the full power of silicon-based information technology. Using the somewhat more advanced process from the semiconductor industry, they can then produce millions of these small microbots from this silicon in just a few weeks. This means that these nanorobots are not assembled, but stamped.

The research team of Marc Miskin from the Cornell University is not satisfied with this. The scientists are already in the process of further developing their microrobots. Bts with more sensors and controllers are planned to make them more intelligent so that they can be used in a wider range of applications, and also energy sources other than light are planned. The researchers would consider magnetic fields or ultrasound, because the advantages of these energy sources would be that they could get better and deeper the human body than light and this would make the use of microbots for the whole body possible without restrictions.

_{source of Informations:
Cornell University - researchGate - nanoWerk
Images: 1, 2 --- Video: Robot Reporters}