Supercritical Snapping and Controlled Launching via Dual Latch Gels

TL;DR

This paper introduces a dual-latched magneto-elastic shell that mimics natural latch-mediated systems, enabling controlled, high-power snapping and launching in engineered materials through integrated mechanical and magnetic latches.

Contribution

The study presents a novel dual-latched LaMSA system with magnetic and intrinsic latches, allowing flexible control of energy release and untethered launching capabilities.

Findings

Demonstrated supercritical snap-through with power amplification

Achieved controlled activation of latches for energy regulation

Enabled untethered directional launching from substrates

Abstract

Natural organisms have evolved integrated Latch-Mediated Spring Actuation systems (LaMSA) that consist of multiple latches and springs to enhance power output and adapt to diverse environmental conditions. Similar designs are appealing yet largely unexplored in engineered materials due to the complexity of integrating multiple components into a single material platform. Here, we report a dual-latched magneto-elastic shell device capable of selectively activating the latches to regulate snapping pathways and energy output based on specific actuation requirements. Differential deswelling across the thickness acts as the motor to load the elastic energy into the shell, which is then released via the snap-through instability once the loading reaches the critical threshold, constituting an intrinsic mechanical latch. Activation of the external magnetic latch delays snapping onset beyond the threshold of the intrinsic latch, leading to a power-amplified supercritical snap-through instability as well as a bifurcation instability. The combined function of both latches allows for flexible control over energy storage and release. Additionally, this integrated LaMSA system possesses an untethered anchoring mechanism, enabling the device to launch in arbitrary directions from the substrate, driven by the energy released during snapping. We envision that the design principles of dual-latched LaMSA systems will create opportunities for power-dense actuation in engineered materials and robotic devices.