This study presents an electromagnetically-actuated reciprocating pump for high-flow-rate microfluidic applications. The pump comprises four major components, namely a lower glass plate containing a copper microcoil, a middle PMMA plate incorporating a PDMS diaphragm with a surface-mounted magnet, upper PMMA channel plates, and a ball-type check valve located at the channel inlet. When an AC current is passed through the microcoil, an alternating electromagnetic force is established between the coil and the magnet. The resulting bi-directional deflection of the PDMS diaphragm causes the check-valve to open and close; thereby creating a pumping effect. The experimental results show that a coil input current of 0.4 A generates an electromagnetic force of 47 mN and a diaphragm deflection of 108 μm. Given an actuating voltage of 3 V and a driving frequency of 15 Hz, the flow rate is found to be 13.2 mL/min under zero head pressure conditions.

The purpose of this study is to develop a micro electro-magnetic actuator manufactured by MEMS-based fabrication and electroplating techniques. This actuator presented a novel technique in the electromagnetic fabrication and smaller physical size than the traditional counterparts for micro actuators and provides a faster response time and lower cost. A micro coil structure is released from FeCl3 etchant and bonded on a thin film (Parafilm”M”, Pechiney Plastic Packaging Inc.) to achieve an actuator-membrane structure. When an external AC power is applied to a micro coil, a magnetic field is created to attract and repel through an NdFeB permanent magnet, and the displacement of the membrane is increased as a current of AC power. The results show the measured magnetic field intensity weakens as the distance between the coil and the Gauss meter probe increases. However, it is observed that the magnetic field intensity does not increase linearly with the number of series coils, which is due to the distance between series coils.