Thermal management is an integral part of micro-heater design. In this paper, the application of a microcavity concept is introduced. The thermal behavior of the proposed novel structure is also numerically investigated in this research to indicate its capability to improve the micro-heaters efficiency and eliminate the common problems of membrane-type heaters. The numerical simulation of the heater structure shows that by using this approach, not only a considerable decrease in power consumption of micro-heaters is attained but also the bubble nucleation point in micro-pumps/micro-injectors can exactly be controlled. As a result, the lengthening of rectangular micro-cavities can contribute to improving heater operation to a greater extent than thickening them. Having a more simple manufacturing process, micro-heater yet has very similar thermal operation characteristics in comparison with bonded heaters.