1.5-cm hydrogen-water micro actuator delivers over 20 N and 7200 cycles without refueling

Researchers demonstrated a laboratory prototype combustion actuator that regenerates its fuel from water by electrolysis, removing the need for external refueling.

A research team reported in Science Advances a 1.5-centimeter combustion-based micro actuator that regenerates its own fuel. It generates forces above 20 newtons and operates for more than 7200 cycles without refueling science.org.

Combustion gives micro actuators powerful impulsive action comparable to that of natural organisms, but dependence on external fuel limits their development. The authors propose a closed-cycle strategy: hydrogen and water are interconverted in both directions, so electrolysis and combustion reactions replenish the reactants in real time.

According to the authors, the number of cycles without refueling is two orders of magnitude higher than for existing combustion-based actuators. Experiments covered removing obstacles, jetting, and striking via underwater cavitation across different environments. The authors say the actuator can be integrated into small robotic platforms so that they can actively reconfigure their local surroundings.