Cost-effective template development for the microfluidic device

Abstract

Photolithography, typically used to create microchannel networks on silicon to fabricate the template for microfluid devices, has the drawback of requiring sophisticated instruments, available only in few premier fabrication units. Template fabrication thus was a privilege of few researchers. Through the years, researchers economised the process of device development using a three-dimensional (3D) printer which directly projected non-planar structures on to a photo-curable resin. Devices thus built lacked the versatility of polydimethylsiloxane (PDMS). The novelty of this work is to use the 3D printing resin for template fabrication and subsequent device development with PDMS. In this way, cost reduction and ease of template generation are substantially enhanced while retaining the advantages of a PDMS device. Unlike directly printed devices that are formed from ultraviolet curable photopolymer, this method fabricates the master with cured photopolymer used in 3D printing. The master pattern is transferred to PDMS for subsequent processing to construct the device. Compared to devices built on silicon templates, PDMS on polymer templates necessitate careful curing at a lower temperature. Low-temperature PDMS–substrate bonding has also been studied in this work. Fabricated device has channel dimensions in the order of 200–300 μm and has been used to study various oil–water emulsions.