Shear Property Characterization for Agarose Gel

Abstract

Hydrogels are hydrophilic polymer networks. They have a defined geometry, which gives them solid like characteristics. Hydrogels also exhibit liquid like nature since certain soluble molecules diffuse through the hydrogel matrix. These characteristics of hydrogel make it extremely difficult to determine the mechanical properties through conventional methods. A new in-plane shear test method that incorporates 3D printed parts and digital image correlation (DIC) was developed. 3D printed parts were used as loading fixture to ensure the appropriate grip on the hydrogel. DIC was used to measure the properties and validate the test methodology. It was identified that shear modulus could be calculated to within 5% coefficient of variation at about 20% strain. Future research will identify ways to increase the limit of the stress-strain curve for calculating shear properties.