HEMI Seminar: Bistable Architected Elastomer Beam Unit: Design & Liquid Crystal Elastomer Re-Programming

Description

The Hopkins Extreme Materials Institute (HEMI) is pleased to welcome David Yoo and Nathan Hertlein for a seminar titled, "Bistable Architected Elastomer Beam Unit: Design & Liquid Crystal Elastomer Re-Programming." Read the speakers' bios online.

This talk can also be viewed online.

Snap-through buckling instabilities are a key driver of multistability in many architected elastomers, which can find applications in fields like energy absorption, vibration isolation, and energy storage. Our research seeks to tune these behaviors by focusing on the unit cell design, taken as a 2D tilted, constrained elastomeric beam. We propose a Fourier series-based beam design parameterization, which covers a large portion of all possible beam designs with a very small number of design variables. This facilitates highly efficient Bayesian optimization, which can be used to tune unit cell energetics and kinematics in few iterations. Moreover, liquid crystal elastomer (LCE) enables a re-programmable stiffness field, which is governed by the applied strain during UV-induced re-programming of mesogen alignment. Therefore a number of mechanical behaviors can be potentially achieved in a single design without requiring alterations of the geometry. By exploring the relationship between applied strain at re-programming and subsequent behavior change, we begin to understand how material properties can be leveraged to modulate mechanical behavior, e.g., buckling mode & post-buckled shape.