Mechanics of Stimuli-Responsive Membrane-Based Materials

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

Membrane-based materials possess fluid compartments separated by thin bilayer membranes. These membranes are capable of mimicking cell membranes, and carefully arranged membrane networks have been considered for use in engineering applications ranging from hearing aids to actuators. This award supports fundamental research on the ability of the membrane to convert mechanical force into meaningful outcomes such as energy conversion and controlled diffusion through the material network. The goal of this work is the advancement of a low-cost material that is simple to assemble while still useful for industries ranging from pharmaceuticals to renewable energy. The research is highly interdisciplinary, combining mechanical, electrical, biological, and chemical engineering. Results from this award will be used to promote interdisciplinary research projects and to develop open-source educational tools and predictive modeling software. There is evidence that these membrane-based materials may be activated and controlled by mechanotransduction, harnessing the unique emulsive elasticity of the material. The multiphysics interactions between applied mechanical force and the response of the internal membranes are not well characterized, requiring new models and experiments for their study. This hypothesized link between material deformation and membrane activity is investigated in detail through this award, creating mechanical models linking the deformation of the bulk material to subsequent deformations of the internal membranes. This task is accomplished through coupled experimental and theoretical work. First, large networks of the membrane-based material will be created. Then these networks will be deformed through various methods including bulk displacement, magnetic forces, osmotic shocks, and high-frequency vibration. Each of these methods for material excitation produces different responses in the interfacial membranes, and will allow for the determination of parameters such as the bulk modulus, stiffness, and damping of the material components. These values will be used to populate models for the material deformation, wherein the material will be simulated as collections of fixed-volume compartments with variable surface elements and contours, examining the dynamic changes in material morphology. This project is designed to address the gaps in current models for the mechanical deformation of the material, and will illustrate the necessary parameters for meaningful mechanotransduction in membrane-based materials.