Low-cost rapid prototyping for microfluidics using Parafilm®-based microchannels for low resource settings

Abstract

We presented a novel strategy of using Parafilm® sheets for making microchannels in rigid substrates-based microfluidic devices with fast prototyping and cost-effectiveness. The strategy uses a Plotter cutter and Parafilm® sheets via the Thermal fusing bonding method to prepare Rigid substrate-based Microfluidics (PPTRμ) in a short span of ∼ 10 min. The Cricut® Explore plotter cutter, as a cheaper alternative to conventional laser cutters, with a ∼ 500 µm resolution to Parafilm® sheet, was shown to create sharp angle micropatterns with a uniform angular distribution. Process parameters like sealing temperature were optimized to minimize channel deformation and enhance device sealing. A 55 °C sealing temperature shows sufficient bonding strength and ensures minimal microchannel width deformation (< 5%). Parafilm® sheets used to make the microchannels showed good chemical resistance to different pH and polar solvent environments. The practical use of the PPTRμ protocol to prepare a two-dimensional concentration gradient generator and a microfluidic electrochemical transducer was successfully demonstrated. The same protocol was extended by appropriately extending the sealing time to 10 min to prepare a three-dimensional microfluidic device with a hybrid structure of "glass-Parafilm®-glass-Parafilm®-glass."