RESEARCH

Development of a Predictive Multiscale Traumatic Brain Injury Model

(Multi-PI Initiative with Ron Szalkowski (Team Wendy), D. Hoffman-Kim, H. Kesari (Brown), L. Lamberson (Drexel), C. Hovey (Sandia))

Luke Summey, Jing Zhang

Successful protection and prevention of traumatic brain injuries requires a complete understanding of the small-scale, cellular response to the mechanical insult. Through extensive collaboration between our lab with Team Wendy, Drexel University, Sandia National Laboratories and the Office of Naval Research, this project establishes a comprehensive framework for identifying the onset of TBI in the brain and a new bottom-up approach for transformative material mitigation and brain treatment strategies.

foam_compression_final2.gif

Light-weight, high-porosity (>80%) polyurethane foams are currently employed in many consumer applications from shoe insoles to soft body armor due to their exceptional energy dissipation potential. Yet their constitutive response remains poorly understood and poses a major obstacle in unlocking their true material potential.

Hypothesized to be a potential injury mechanism in blast and even blunt related traumatic brain injuries, inertial microcavitation is a powerful phenomenon capable of generating significant stresses and strains within brain tissue at hyper ballistic loading rates. This project aims to detail this new injury mechanism and its underlying neural pathology. 

cavitation.gif

Development of a Multiscale Experimental-Numerical Framework for Characterizing Inertial Cavitation in Complex Soft Matter

(Multi-PI Initiative with E. Johnsen, Z. Xu (Michigan), D. Henann (Brown), and T. Colonius (Caltech)

As opposed to traditional cavitation studies focused on understanding the physical behavior of expanding and collapsing bubbles in water or against metallic interfaces, this project focuses on understanding the physics of cavitation in complex soft materials. In particular, understanding how the rate-dependent, finite deformation behavior of length and time scale dependent compliant polymers affect the pressure, stress and strain fields in cavitating bubbles is investigated.

Optically Measuring the Electrophysiology of Neurons Under Tension Using a Novel Voltage-Sensitive Dye

(in collaboration with Aviad Hai (Wisconsin) and Andrea Armani (USC))

The electrophysiology of neurons is important to understand as it contributes greatly to the function of the brain and the communication of the brain to different parts of the nervous system. This project aims to examine the change in neuronal activity during and after tension loading that simulates a traumatic brain injury. Using a fluorescent dye newly developed by the Armani Lab, this project will verify the accuracy of the dye as a way to obtain clear, meaningful electrophysiological data without the need for intracellular or extracellular electrical devices..