Autonomous Microrobots Developed by Penn and Michigan Reach Sub-Millimeter Scale

Researchers from the University of Pennsylvania and the University of Michigan announced in January 2026 the creation of the world's smallest fully autonomous and programmable robots. These microrobots measure approximately 200 by 300 by 50 micrometers, a scale comparable to the width of a human hair. This development marks a critical advance as these are the first autonomous robots at this scale capable of operating without external tethers, magnetic fields, or direct remote manipulation, with details published in the peer-reviewed journals Science Robotics and Proceedings of the National Academy of Sciences (PNAS).

Each unit is manufactured at an estimated cost of one cent and is designed for extended operation, lasting several months by drawing power exclusively from ambient light captured by integrated photovoltaic cells. Overcoming a significant energy constraint, the team engineered specialized circuits to operate at extremely low voltages, reducing power consumption by over a thousand times compared to conventional systems. The microscopic solar panels generate only 75 nanowatts, necessitating a complete redesign of the computational architecture to function within this minimal power budget, which is more than 100,000 times less than the consumption of a standard smartwatch.

The method of propulsion addresses the physics of the microscale, where viscous drag dominates. Rather than physically displacing the liquid medium, the robots generate localized electric fields that induce movement in the charged ions within the surrounding fluid. The resulting drag from these agitated water molecules creates the net flow that propels the robot forward. By precisely modulating these electric fields, the microrobots can execute pre-programmed trajectories and demonstrate synchronized group behaviors.

True autonomy is achieved through the integration of sensing, information processing, and decision-making capabilities on an onboard chip smaller than a millimeter. This integration resulted from the collaboration between Mark Miskin of the University of Pennsylvania and David Blaauw of the University of Michigan, whose laboratory previously developed the world's smallest computer. Researchers can receive environmental data, such as temperature readings, from the robots through coded, patterned movements, a communication method analogous to the signaling 'dance' of honey bees.

This technological breakthrough, which resolves a technical impediment that had previously stalled progress in sub-millimeter autonomy for nearly four decades, presents significant potential across various sectors. In medicine, these devices could be used for monitoring individual cell health or enabling highly targeted drug delivery to specific pathological sites. Furthermore, their low production cost and inherent durability, derived from the absence of fragile moving parts, position them as viable candidates for microscale manufacturing processes. Researchers are also exploring applications for in-vivo use, noting that certain light wavelengths can penetrate human tissue, while alternatives like ultrasound are being considered for deeper environments.