An electrochemical actuator is demonstrated that uses the periodic explosions of hydrogen and oxygen gases in a microchamber with a volume of 3.1 nl. The gases are generated in the form of nanobubbles during alternating  polarity electrolysis. The device operates at a frequency of up to 10 Hz. The stroke of the membrane can reach 100 μm, which is an order of magnitude larger than the deflection in the non-explosive mode. No significant wear of the  device is observed after 40 000 explosions in the chamber. The output force is measured by loading the membrane with different objects. The actuator develops a force at least 0.5 N, significantly outperforming other actuators in  terms of force density.