BME Seminar: “Mechanics of Failure in Medical Devices and Soft Materials”

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Chase Hartquist, Ph.D.
Assistant Professor, Mechanical and Aerospace Engineering
University of Florida

Abstract: Soft networks of interconnected polymer chains permeate throughout nature, biology, and technology due to exceptional mechanical performance. Engineering biomedical materials and devices to be compatible with biology can offer solutions to longstanding problems in medicine. However, mechanical failure remains a key bottleneck in developing this interface. This seminar explores two challenges across medical devices and soft materials where fracture and failure mechanics offer solutions. First, in vascular surgery, a class of sudden failures called “herniation” occurs commonly during navigation of surgical tools. Here, a bent region of the device buckles while traversing an anatomical curve, causing the surgeon to lose control of the distal tip. This typically requires reintervention with new devices. We show that herniation can be predicted by investigating it as a bifurcation phenomenon and prevented by changing catheter design and selection paradigms. Second, in soft materials, while traditional models predict the intrinsic fracture energy of a polymer network is the energy to rupture a layer of chains, they can underestimate experiments by up to two orders of magnitude. We show that the intrinsic fracture energy of polymer-like networks stems from nonlocal energy dissipation using experiments and simulations of 2D and 3D networks with varying defects, dispersity, topologies, and length scales. Collectively, these works connect failure mechanics across scales and provide design rules for soft devices and materials.

Bio: Chase Hartquist is an Assistant Professor in the Department of Mechanical and Aerospace Engineering at the University of Florida. He obtained his Ph.D. in Mechanical Engineering at the Massachusetts Institute of Technology, where he investigated the mechanics of fracture in soft network materials. He earned his B.S. and M.S. in Mechanical Engineering from Washington University in St. Louis, where he studied the mechanics of vascular surgery and biomedical materials. His research focuses on understanding the mechanical and failure behaviors of soft structures, networks, and polymers. This work leverages fundamental structure-property relationships across length scales to inform design of high-performing soft materials and structures for emerging applications in medical technology and clean energy.