Experimental study of bubble dynamics on a micro heater induced by pulse heating

An experimental investigation of the rapid formation and collapse of bubbles formed on a micro heater (25 x 80 mum(2)) is presented. Short electric pulses in the range of 1 mus to 4 mus are applied to the resistive heater, which is immersed in deionized water and generates a heat flux of more than 750 MW/m(2). A stroboscopic technique with a time resolution of 30 ns and spatial resolution of 2 mum was used to capture the dynamics of the bubble growth and collapse. From the nucleation theory, the nucleation temperatures are close to the kinetic limit of superheat and weakly depends on the heating rate. The velocity, acceleration, and the pressure profiles after the vapor sheet formation are presented.