Smart Microscopic Robots*

Microscopic robots – robots a few hundred micrometers in size or smaller – have huge potential for applications in numerous fields, from medicine to environmental remediation to studying emergent behavior in robot swarms. However, no previously reported microscopic system can be programmed to accomplish complex tasks autonomously, the dictionary definition of a robot. Here, we report the creation of microscopic robots that meet this standard. We build these robots by integrating electronically controlled microactuators with complementary metal oxide semiconductor (CMOS) electronics. The resulting robots are 100 – 250 micrometers in lateral dimension, are powered by light, and can actuate their legs independently and walk autonomously at speeds greater than 10 micrometers per second without any input of information. We also demonstrate microscopic robots that change their behavior in response to an optical command. This work paves the way for smart microscopic robots that can sense and respond to their environment, receive commands, perform complex functions, and communicate with the outside world.