Rapid and low-cost development of microfluidic devices using wax printing and microwave treatment

Abstract

Wax printing is a print-and-peel (PAP) rapid prototyping technique that enables rapid creation of master molds for miniaturized polydimethylsiloxane (PDMS) systems, circumventing the need for specialized microfabrication personnel and facilities. We have demonstrated wax printed molds with microwave thermal processing to cure PDMS (25 min) and thermally anneal PDMS to glass (30 min), representing one of the fastest non-lithographic methods for the fabrication of PDMS microfluidic structures to date. The smallest fabricated features are on the order of 350 μm wide and 5 μm tall. Three devices were fabricated using this technique, including a microfluidic gradient generator, a T-droplet generator, and a Y-channel microfluidic device, with performance comparable to literature devices fabricated via traditional photolithography. Direct comparison between Y-channel devices made with the new rapid prototyping technique and with standard photolithography showed similar laminar flow performance, and thus the feasibility of our method. We have demonstrated device fabrication from design phase to testing within one hour, thus our innovative method significantly speeds up the development of microfluidic tools.