Researchers from the University of Pennsylvania and University of Michigan just shattered a 40-year robotics challenge, building the world's smallest fully autonomous robot at just 0.3 millimeters - smaller than a grain of salt. The breakthrough device can sense its environment, make independent decisions, and swim underwater for months powered only by light, all while costing just 1 cent per unit to manufacture. This marks the first time engineers have successfully miniaturized a complete autonomous robot below the 1-millimeter threshold that's stumped the field for decades.
The race to miniaturize robotics just hit a historic milestone. A joint team from the University of Pennsylvania and University of Michigan announced they've built a fully autonomous robot measuring just 200 x 300 x 50 micrometers - roughly 0.3 millimeters on its longest side. That's smaller than a grain of salt and far below the 1-millimeter threshold that's eluded engineers for four decades.
"We've succeeded in miniaturizing an autonomous robot to 1/10,000th the size of a conventional robot," Mark Miskin, assistant professor of electrical systems engineering at Penn, told the university in a public statement. "This opens up a whole new scale for programmable robots."
The breakthrough isn't just about size. These microscopic swimmers can sense their surroundings, make independent decisions, and operate for months without any external controls like wires or magnetic fields. The team published their findings in Science Robotics this week, documenting how they overcame fundamental physics problems that change dramatically at microscopic scales.
The propulsion system represents a complete departure from conventional robotics. While fish and larger organisms swim by pushing water backward - following Newton's third law of motion - that approach fails at microscopic scales where water viscosity becomes overwhelming. "Pushing water on a microscopic scale is like pushing sludgy tar," the researchers explain in their paper.
