Comparison between Injection Molding (IM) and Injection‐Compression Molding (ICM) for Mass Manufacturing of Thermoplastic Microfluidic Devices

Abstract

Point‐of‐care (PoC) and organ‐on‐chip (OoC) devices represent promising microfluidic applications for in vitro analysis and miniaturized analytical studies, reducing the need for traditional animal‐based tests for drug discovery and toxicity studies. Using thermoplastics in microfluidic device manufacturing provides interesting functionalities for expansion of these devices into market. However, market growth requires manufacturing large quantities for low cost, which can be achieved using injection molding techniques. This work involves the design of a microfluidic device with different aspect ratio channels to compare injection molding (IM) and injection‐compression molding (ICM) processes, as well as the design and manufacturing of a metallic insert containing machined inverted microstructures. Injected parts are validated visually, dimensionally, and functionally. The differences between both techniques and two grades of cyclic olefin copolymer materials are analyzed to evaluate microfluidic device mass production feasibility concluding that although the machining process for inverted high aspect ratio microstructures is not mature yet, both IM and ICM processes allow the mass manufacturing of microfluidic devices in thermoplastic. Parts processed by ICM show better replicability of microfluidic structures and less internal stresses generate during the injection process than IM parts, highlighting the potential of this process to achieve thermoplastic microfluidic devices to market.