Mechanical and Civil Engineering Seminar

Title: "Building the Tools for a New Generation of Intelligent Ionic Materials"

Abstract: Soft ionic circuitry, formed from ions moving through materials, promises to enable smart, active materials that can sense, process, and respond to their environment. Since the 1950s, these circuits have evolved from individual components into an expanding library of sensors, actuators, signal transmitters, and processors. However, integrating these components into complex, multifunctional systems remains challenging, due to gaps in device understanding, design, and manufacturing. In this talk, we discuss work addressing each of these gaps in turn. First, using a continuum model for ionic materials and charge transport, we analyze the transient response of the simplest functional ionic device, a diode, identifying which material and geometrical properties govern its behavior and how that behavior contrasts with traditional semiconductors. Second, inspired by electronic circuit design tools, we develop a lumped-element model that captures features specific to ionic charge carriers while preserving the hierarchical flexibility and computational efficiency of traditional circuit modeling. The model not only fits individual device behavior but predicts the behavior of larger circuits built from those devices. We apply it to design the control system for a soft robot and to explain the behavior of an experimental ionic haptic surface with dynamically tunable stiffness. Finally, we develop a manufacturing technique that directly writes ionic circuitry onto thermoelastomeric rubber, yielding feature sizes of tens of microns while preserving the mechanical properties of the underlying substrate to create circuitry that is both stretchable and high-resolution.

Bio: Max Tepermeister received a Bachelor of Science degree from Harvey Mudd College in 2020 and a PhD from Cornell University in 2025. His worked has focused on forming novel devices from ionic polymers, using machine learning to decipher biological and chemical systems, and broadening the application of systems analysis tools to polyelectrolytes. He is particularly interested in how ionic polymers and gels can form the basis for a new class of robotic and medical devices, and has worked on these problems from a variety of angles, including lumped and continuum simulations, polymer synthesis and characterization, and device design and fabrication. In his free time, he plays boardgames, participates in the AViEn ensemble, and dances social swing and ballroom.