Affiliation:
1. Valiev Institute of Physics and Technology Russian Academy of Sciences, Yaroslavl Branch Universitetskaya 21 Yaroslavl 150007 Russia
2. Frumkin Institute of Physical Chemistry and Electrochemistry Russian Academy of Sciences Leninsky prospect 31 bld. 4 Moscow 119071 Russia
Abstract
AbstractThe 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 107 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.