https://illinois.zoom.us/j/82660723333?pwd=wr4yqbQFhZMmzi6KvnohaWts9qZZI2.1
Meeting ID: 826 6072 3333
Password: 606764
Topology optimization and physical realization of magnetically active materials: from reprogrammable metamaterials to biomedical robots
Advisor: Professor X. Shelly Zhang
Abstract
Magneto-actuated soft materials have garnered growing interest due to their ability to undergo rapid, remote, and controllable deformation under applied magnetic fields. These materials have shown promise across a range of applications, including soft robotics and biomedical devices. In particular, hard-magnetic soft materials, made of a soft elastic matrix embedded with hard-magnetic particles (can retain high remanent magnetization), offer exceptional programmability and flexibility.
As an initial exploration in the design optimization for this material, we develop a comprehensive topology optimization framework for hard-magnetic soft materials to guide the rational design with programmable actuation under large deformations. This framework simultaneously optimizes the material topology, remanent magnetization distribution (selected from several candidate directions), and external magnetic field directions, enabling the design of soft robots and actuators.
Building on this foundation, we extend the framework to enable magneto-actuated reprogrammability, where a single design can exhibit a desired response under purely mechanical loading and transition to a different response when subject to both mechanical and magnetic stimuli. We also discover magnetically active structures showcasing a broad spectrum of tunable buckling mechanisms with experimental investigations, including programmable peak forces and buckling displacements, as well as controllable mechano- and magneto-induced bistability.
To further expand the design space and facilitate designs that are highly compatible with advanced additive manufacturing techniques such as direct-ink-writing, we develop a parametrization method that enables designs with spatially continuous magnetization transitions and locally arbitrary magnetization orientations. The optimized designs are highly compatible with the direct ink writing process, as demonstrated through successful fabrication and experimental validation.
In addition, we expand the design framework for hard-magnetic soft materials with electrets (immobile charges) inducing coupled electric field. These magnetoelectric materials generate electric output through magnetically induced deformation and deformation-induced charge redistribution. We successfully optimize these structures for both charge generation and target deformation modes. We present several application-driven designs including therapy robots that deliver combined mechanical and electrical stimulation. We conduct tailored fabrication and experiments for optimized magnetoelectric designs. Additionally, we develop multi-functional devices capable of providing target deformation and electricity generation, potentially for self-powering or self-sensing. As a proof of concept, we demonstrate such designs can generate sufficient electric power to power an LED. These results highlight the potential of our framework for next-generation magneto-mechano-electric biomedical devices.