Integration of Heteromaterial Microelements into Plastic Microfluidic Devices by Capillary-force-assisted Micromolding

Abstract

We propose an advanced micromolding process for integrating heteromaterial micro- elements with complicated structures into a plastic substrate. The technique comprises the autonomous filling of dispensed liquid prepolymers into microstructures pre-engraved on a plastic substrate and subsequent curing to induce the cross-linking of the prepolymers. Specifically, the fabrication of a self-standing poly(dimethylsiloxane) elastomer membrane into a rigid plastic substrate has been investigated. Based on the experimental results, a guiding principle for the dimension control of the finally formed structure is discussed by considering the balance between the capillary force and gravity acting on the liquid prepolymer. Moreover, the present technique has been preliminarily applied to a lab-on-a-chip technology: the implementation of elastomer-based pneumatic microvalves on plastic-based microfluidic devices.