Narrative

Graduate mechanical engineering researcher Dongjing He’s work involves characterizing the mechanics of soft materials using applied math and physics. He presses down on polymeric gels, such as hydrogel, with a microscopic glass sphere, and measures how the gel displaces based on the force applied. This process is called indentation, and has led to important discoveries about the structure of gels. For example, Fig 1 (from He and Yuhang Hu’s paper Nonlinear Visco-Poroelasticity of Gels With Different Rheological Parts), shows how a gel is composed of a crosslinked polymer network and how the polymer network deforms. It also explains poroelasticity, which occurs when a force is applied to a gel and the solvent molecules are displaced a long distance. In nature and engineering, many materials can be classified as a soft gel, so understanding their mechanics is crucial within multiple areas, for example blood clots, artificial organs, and hydrogels for tissue engineering. The art piece is meant to symbolize a hydrogel’s cross linked polymeric network, with the solid sphere acting as an indentor that displaces the “water molecules”.The artist utilized soft body dynamics, a feature within computer graphics, to realistically simulate the mechanical properties of a gel.