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Abstract The development of fast and strong microactuators that can be integrated in microdevices is an essential challenge due to a lack of appropriate driving principles. A membrane actuator powered by internal combustion of hydrogen and oxygen in a chamber with a volume of 3.1 nanoliters is demonstrated. The combustion in such a small volume is possible only for an extremely high surface‐to‐volume ratio on the order of 10 7 m −1 . The fuel with this ratio is prepared electrochemically in a special regime that produces only nanobubbles. A cloud of nanobubbles merges, forming a microbubble, which explodes, increasing the volume 500× in 10 µs. The actuator generates an instantaneous force up to 0.5 N and is able to move bodies 11 000× more massive than itself. The natural response time of ≈10 ms is defined by the incubation time needed to produce an exploding bubble. The device demonstrates reliable cyclic actuation at a frequency of 1 Hz restricted by the effect of electrolyte aging. After 40 000 explosions, no significant wear in the chamber is observed. Due to a record‐breaking acceleration and standard microfabrication techniques, the actuator can be used as a universal engine for various microdevices including microelectromechanical systems, microfluidics, microrobotics, wearable and implantable devices.
Uvarov et al. (Wed,) studied this question.