Electrothermal static micro-pump with fluid-pressure-operated valve - drives liq. past resilient flap into outlet by expansion of vapour bubble generated by electric heating element

摘要

The pump has the heating element (2) on the floor of a liq.-filled chamber (4) in a monocrystalline Si structure to generate a bubble (14) of vapour in the space between an inlet constriction (8) and an outlet which is controlled by a flap valve (12). The fluid-mechanical impedance of the valve is less than that of the constriction so that instead of "blowing back" into the inlet (6), the bubble opens the valve before contracting to allow more liq. to enter. ADVANTAGE - Very compact pump, improves action with high capacity and reliability over long period, having no moving parts other than static valve(s).