Bubble nucleation on micro line heaters

Nucleation temperatures on micro line heaters were measured precisely by obtaining the I-R (current-resistance) characteristic curves of the heaters. The bubble nucleation temperature on the heater with 3 pun width is higher than the superheat limit, while the temperature on the heater with broader width of 5 mum is considerably less than the superheat limit. The nucleation temperatures were also estimated by using the molecular cluster model for bubble nucleation on the cavity free surface with effect of contact angle. The bubble nucleation process was observed by microscope/35 nun camera unit with a flash light of mus duration.