Ionic diodes, created at the intersection of polymers with different fixed charges, form the core of many ionic devices. Despite this centrality, the time dependent behavior of these diodes is not well understood. In a new paper published in Advanced Sensor Research and led by PhD candidate Max Tepermeister, we use a finite-volume based continuum simulation to explain how geometry and material properties influence each stage of a diodes transient response. We show that how a diode connects to a larger circuit can dramatically change its performance, and we develop a consistent set of metrics to quantify these differences and provide a basis for future device comparisons. Using what we learned, we make recommendations for tuning performance by changing how diodes are built.

Our research paper “Elucidating the impact of microstructure on mechanical properties of phase-segregated polyurea: Finite element modeling of molecular dynamics derived microstructures” is now published in Mechanics of Materials. This study was led by Dr. Steven Yang, who recently completed his PhD in the lab, in collaboration with Dr. Stephanie Rosenbloom and Prof. Brett Fors from Cornell Chemistry. We developed a modeling framework to uncover how the phase-segregated nanostructure of polyurea influences its mechanical properties. This work integrates a wide range of methodologies, including molecular dynamics and finite element simulations, constitutive theory, and both mechanical and X-ray scattering experiments.

https://doi.org/10.1016/j.mechmat.2023.104863