Fabrication of PDMS microfluidic chips used in rapid diagnosis by micro jetting

Abstract

In this paper, a simple method was demonstrated to fabricate polydimethylsiloxane (PDMS) microfluidic chips used in rapid diagnosis based on printing the liquid molds directly. The liquid droplets were jetted by a glass micronozzle onto the hydrophilic glass substrate based on microfluidic pulse interior force to form various liquid molds, and then a replication process and a bonding process were followed for the fabrication of PDMS microfluidic chips. The effects of the wettability of the substrate and the overlap between the droplets on the formation of the liquid molds were investigated. Liquid molds with width ranging from 40 μm to 365 μm were prepared with an aspect ratio of 0.080 through controlling the overlap and the droplet size. The surface of the fabricated microchannels was smooth as the arithmetical mean deviation of the profile Ra was 179.1 nm with the 80 × 320 μm2 area at the bottom. The microreactions at the well-defined interfaces of several different solutions were realized with the fabricated PDMS microfluidic chips.