A Combined Analytical–Numerical Investigation on Photosensitive Hydrogel Micro-Valves

Abstract

In this paper, employing photo-thermal sensitive (PTS) hydrogels, a photosensitive bio-compatible micro-valve is investigated. In this regard, the energy representation and governing equations of PTS hydrogels are described. Two benchmark problems common in micro-fluidic designs are solved using the presented theory, and the deformation and stress distributions are calculated. The theory is implemented into a finite element (FE) framework by developing a user-defined subroutine. To properly validate the FE model, the FE results are compared with the proposed analytical results. The confirmed numerical method is then employed to investigate two different realistic micro-valve structures. The constructions are composed of three jacket-pillar structures arranged in two different patterns. In this step, the nonlinear contact between the components of structures and presumptive rigid walls are added to the thermo-mechanical deformation of the photosensitive micro-jackets. The contact length and contact pressure are investigated. By calculating all necessary mechanical parameters, the analysis results can be utilized in the design procedure of a photosensitive micro-valve and pave the way for the industrial production of the next generation micro-fluidic devices.