Microscopic robots can move autonomously thanks to a simple ‘brain’

New microrobots created by Cornell University have a rudimentary "brain" enabling them to move autonomously - unlike most other microscopic robots, which require some form of external control.

The new microrobots are 100-250 micrometers across: they are about 10,000 times smaller than macrobots with built-in CMOS electronics, and they can move at speeds of more than 10 micrometers per second. The new microrobots have a different number of “legs”:

• The two-legged Purcell was named after physicist Edward Purcell, who proposed a similarly simple model to explain the swimming movements of microorganisms.
• The six-legged antbot walks in an alternating tripod gait like an insect.
• The four-legged dogbot can change speed when the operator sends laser pulses.

The brain of the new robots is a complementary metal-oxide-semiconductor (CMOS) structure that contains a thousand transistors, an array of diodes, resistors and capacitors. The integrated CMOS structure generates a signal that creates a series of phase-shifted rectangular waves, which in turn set the robot's gait. The legs of the robot are platinum-based actuators. Both the CMOS structure and the legs are powered by photovoltaics. The robots’ exceptionally low power consumption has spared specialists from having to use relatively large photovoltaics.

So far, the new micro-robots can only “step forward,” but in the future, they could play an important role in a number of areas, such as healthcare: they could be used to perform internal surgeries and clean arteries. As for other possible applications, they could detect chemicals and remove contaminants.

Of course, such micro-robots are still a long way off, but this Cornell University project has shown that they are technically possible.