This autonomous solar-powered robot costs 1p, is smaller than a grain of salt, and communicates through 'wiggles of a little dance'
Robots carry processors, memory, and sensors despite extremely limited space
· TechRadarNews By Efosa Udinmwen published 4 January 2026
(Image credit: Marc Miskin, University of Pennsylvania (via Techxplore)) Share Share by:
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- Researchers created fully autonomous robots smaller than a grain of salt
- Robots swim using electrical fields to manipulate ions in the surrounding fluid
- The propulsion system allows coordinated movement and speeds up to one body length per second
Researchers at the University of Pennsylvania and the University of Michigan claim to have created the world’s smallest fully programmable, autonomous robots.
Each robot measures roughly 200 by 300 by 50 micrometers, smaller than a grain of salt, and operates at the scale of biological microorganisms.
The robots function without tethers, magnetic fields, or external joysticks, making them the first truly autonomous devices of this size.
Swimming through microscopic physics
The team faced challenges creating propulsion systems suitable for such small robots - as at this scale, forces like drag and viscosity dominate, making conventional limbs or body flexing ineffective.
Instead, the robots use electrical fields to manipulate ions in the surrounding fluid. These ions, in turn, push on water molecules, creating movement.
This approach allows the robots to swim in complex patterns and even coordinate in groups, reaching speeds of up to one body length per second.
Because the electrodes generating the field have no moving parts, the robots are extremely durable and can be repeatedly transferred between samples without damage.
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