A polymeric paraffin actuated high-pressure micropump

We present the potentially strongest mechanical micropump in sub-cm3 size yet for microfluidics, using simple processes and materials such as epoxy, paraffin and polyimide. Utilizing the large volume expansion associated with the melting of paraffin for actuation, a pump consisting of two active valves and one pumping chamber operated by three identical paraffin actuators has been realized with a rapid prototyping process. The main construction material is UV curable epoxy, which encloses the paraffin, forms the channel structure and joins the glass cover, actuator membrane and resistive heaters for melting the paraffin. With water as a pumping fluid and a low voltage waveform, a flow rate of 74 nl/min was obtained. The valves were subjected to pressures up to about 1 MPa without showing any leakage.