Development of bi-directional valve-less micropump for liquid

A micropump based on a novel flow rectification principle was developed. Instead of mechanical check valves, the difference of flow resistance in narrow channels caused by the temperature dependence of liquid viscosity is utilized as the basis of the valve effect. This method allows a flexible control of the pump function, including bi-directional pumping. A prototype device actuated by a piezoelectric element was designed and fabricated to confirm the pump function. The fluidic and thermal conditions for the pump actuation, and the characteristics of its behavior revealed by experiments are discussed.