Manipulate microfluid with an integrated butterfly valve for micropump application

Abstract

This paper reports a novel electromagnetic micropump (EMP) that only uses one vibrating integrated butterfly valve (IBV) to manipulate microfluid directly. The IBV, composed of a Polyimide (PI) slice, a moving magnet and elastic silica gel diaphragm, could open or close periodically stimulated by external alternating magnetic field. The micropump is instantaneous fluid pressure-dependent for simple structure by integrating the butterfly valve and moving parts into one valve. In the suction mode, the positive instantaneous pressure pushes the valve, driving the fluid crossing the valve. While in the expelling mode, the negative instantaneous pressure compresses the slice and closes the valve, pushing fluid out. The test results not only show a frequency-dependent flow rate relationship and determine a resonance frequency of 15 Hz, but also give linear curves between flow rate/backpressure and applied current. Furthermore, the designed micropump exhibits a maximum flow rate and backpressure of 9.47 mL/min and 70.5 mmH2O respectively. For its simplicity, this novel micropump technology could be scaled down easily, which could be further integrated and applied in a microsystem.