Chemical Transport Modeling for Polydimethylsiloxane-Based Microfluidic Devices

Abstract

Polydimethylsiloxane (PDMS)-based microfluidic devices (e.g. organ-on-chips) are increasingly important tools in biological sciences and engineering which may investigate biological processes at a miniaturized scale. However, PDMS is known to interact with hydrophobic chemicals and can strongly limit such chemicals’ in-device availability. Through a comprehensive transport model, one can predict in-device chemical concentration through finite element method (FEM) simulations using transport parameters derived from simple experiments. These parameters vary greatly between similar chemicals, revealing the limits of simple “read-across” methods in predicting chemical interaction. Chemicals may also undergo nonlinear transport via anomalous diffusion in PDMS. Through the framework of stretched-time fractional diffusion, this behavior may be characterized and modeled. The application of these methods allows a user of a naïve PDMS-based microfluidic device to extrapolate in-device concentrations under any geometric configuration or dosing regimen.