The explosive micro-bubble actuator is a new type of actuator based on bubble generation by explosive evaporation. It can operate at frequencies up to 5 kHz which is extremely high for a thermo-pneumatic actuator. At these frequencies, the device can still produce a pressure of several bars resulting in a membrane deflection of several micrometers. The influence of the pressure inside the cavity on the performance is investigated. The maximum repetition frequency is related to the formation of permanent gas bubbles. By increasing the pressure in the cavity the influence of these bubbles can be decreased. The cavity pressure proves to be a useful tool to increase the performance of the explosive micro-bubble actuator.