Meet the world's smallest autonomous robots, measuring just 0.2mm

Technology Dec 16, 2025

Scientists at UPenn and UMich have built super tiny, fully programmable robots—about as wide as a grain of salt—that cost only a cent each.
These little machines could shake up how we monitor single cells or build things on a microscopic scale.

How do these mini bots work?

Each robot packs in solar cells, a low-power processor, temperature sensors, and platinum electrodes.
Instead of wheels or legs, they move by creating electric fields that push ions and water around them—no moving parts needed.

What can they actually do?

In lab tests, these bots navigated temperature changes on their own and even "wiggled" to send signals.
Their sensors are accurate within +-0.3°C, making them promising for tasks like tracking what's happening inside single cells or assembling tiny structures in the future.