Design and fabrication of chemically robust three-dimensional microfluidic valves

Abstract

A current problem in microfluidics is that poly(dimethylsiloxane) (PDMS), used to fabricate many microfluidic devices, is not compatible with most organic solvents. Fluorinated compounds are more chemically robust than PDMS but, historically, it has been nearly impossible to construct valves out of them by multilayer soft lithography (MSL) due to the difficulty of bonding layers made of ''non-stick'' fluoropolymers necessary to create traditional microfluidic valves. With our new three-dimensional (3D) valve design we can fabricate microfluidic devices from fluorinated compounds in a single monolithic layer that is resistant to most organic solvents with minimal swelling. This paper describes the design and development of 3D microfluidic valves by molding of a perfluoropolyether, termed Sifel, onto printed wax molds. The fabrication of Sifel-based microfluidic devices using this technique has great potential in chemical synthesis and analysis.

Simple push coating of polymer thin-film transistors

“…1a. We designed a PDMS/fluorocarbon polymer/PDMS trilayer stamp in which the PDMS layers work as both-sided surface-contact layers and the fluorocarbon polymer works as a blocking layer against solvent diffusion22 (Fig. 1b).…”

Rapid prototyping of paper‐based microfluidics with wax for low‐cost, portable bioassay

“…The third way is to print the designed pattern on the filter paper directly using a wax printer (FUJIXEROX Phaser 8560DN, Japan; printer resolution is 2400 dpi  2400 dpi) [8,9]. The printing process is quite simple without the use of wax pen (the height of the wax line is about 10 mm and the thickness of the filter paper is 120 mm in our experiment).…”

High‐Performance Materials for 3D Printing in Chemical Synthesis Applications

“…Besides being chemically very stable, they exhibit high optical transparency to visible light, low surface energy, and tunable elasticity making them interesting candidates for chemically resistant microfluidic valves. [63] Here, 3D printing can make a huge difference since closed channel structures can be directly printed. [59][60][61][62] However, due to their high chemical resistance the bonding of these replicated or directly structured chips remains a major problem.…”

“…[59][60][61][62] However, due to their high chemical resistance the bonding of these replicated or directly structured chips remains a major problem. [63] Here, 3D printing can make a huge difference since closed channel structures can be directly printed.…”