CO2 Laser-Based Rapid Prototyping of Micropumps

Abstract

The fabrication of microdevices for fluidic control often requires the use of flexible diaphragms in a way that requires cleanroom equipment and compromises performance. We use a CO2 laser to perform the standard ablative techniques of cutting and engraving materials, but we also apply a method that we call laser placement. This allows us to fabricate precisely-positioned and precisely-sized, isolated diaphragms. This in turn enables the rapid prototyping of integrated multilayer microfluidic devices to form complex structures without the need for manual positioning or cleanroom equipment. The fabrication process is also remarkably rapid and capable of being scaled to manufacturing levels of production. We explore the use of these devices to construct a compact system of peristaltic pumps that can form water in oil droplets without the use of the non-pulsatile pumping systems typically required. Many devices can be fabricated at a time on a sheet by sheet basis with a fabrication process that, to our knowledge, is the fastest reported to date for devices of this type (requiring only 3 h). Moreover, this system is unusually compact and self-contained.

Low-cost microfluidics: Towards affordable environmental monitoring and assessment

“…(B) PMMA micropump. Reproduced with permission from (Strike et al, 2018). (C) Cross section showing the laser (CO 2 ) cut microchannel.…”

“…(C) Cross section showing the laser (CO 2 ) cut microchannel. Reproduced with permission from (Strike et al, 2018). (D) 3D printed device made out of novel resin (Dowsil 732) that enables end-use devices.…”

Intermediate layer-based bonding techniques for polydimethylsiloxane/digital light processing 3D-printed microfluidic devices

“…Double-sided tape is the simplest form of an intermediate layer for bonding. It has been used to adhere PDMS to glass for micro particle image velocimetry (PIV) measurent devices [13], PDMS to PMMA for a microfluidic device for the observation of perturbation of Drosophila embryos [32], and PMMA to PMMA for droplet formation devices [33]. In our experiment, double-sided tape (3M Double Coated Tape 444, 3M Corp) was simply attached to the surface of a 3D-printed bottom part and the pneumatic port was cut out using a scalpel.…”

Editorial for the Special Issue on Polymer Based MEMS and Microfabrication

“…For the original research articles published in this special issue, polymers are shown to be functional in the most demanding of applications and also exceptionally useful for frugal engineering or rapid prototyping. We have three articles that focus on specific manufacturing improvements that aid in the fabrication of low-cost polymer microfluidics [3,4,5]. Song et al [3] demonstrate a new technique to bond two dissimilar thermoplastics, polycarbonate (PC) and polymethylmethacrylate (PMMA) via a PMMA solution dissolved in propylene glycol monomethyl ether acetate (PGMEA).…”

“…The integration technique is relatively simple, has very low cost materials like commercial acrylic, tape and food wrap, and was demonstrated to be functional for a simple application of two-phase water in oil droplet generation, with a fabrication time of a few hours. Zhou et al [5] provides an alternative manufacturing technique for PMMA in microfluidics as high precision milling of a PMMA master mold is used, which can then be subsequently replicated to make polydimethylsiloxane microfluidic systems. Much smaller channels can be produced using a large milling tool when making a positive relief than if it was to mill out channels directly, and the roughness and minimum features were tested before and after PDMS replication to determine tolerances and fidelity.…”