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Abstract Actuators utilizing snap‐through instabilities are widely investigated for high‐performance fast actuators and shape reconfigurable structures owing to their rapid response and limited reliance on continuous energy input. However, prevailing approaches typically involve a combination of multiple bistable actuator units and achieving multistability within a single actuator unit still remains an open challenge. Here, a soft actuator is presented that uses shape memory alloy (SMA) and mixed‐mode elastic instabilities to achieve intrinsically multistable shape reconfiguration. The multistable actuator unit consists of six stable states, including two pure bending states and four bend‐twist states. The actuator is composed of a pre‐stretched elastic membrane placed between two elastomeric frames embedded with SMA coils. By controlling the sequence and duration of SMA activation, the actuator is capable of rapid transition between all six stable states within hundreds of milliseconds. Principles of energy minimization are used to identify actuation sequences for various types of stable state transitions. Bending and twisting angles corresponding to various prestretch ratios are recorded based on parameterizations of the actuator's geometry. To demonstrate its application in practical conditions, the multistable actuator is used to perform visual inspection in a confined space, light source tracking during photovoltaic energy harvesting, and agile crawling.
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This content will become publicly available on October 17, 2026
Multistable thin-shell metastructures for multiresponsive reconfigurable metabots
Multistable metastructures can switch between multiple stable configurations without requiring locking forces. However, their potential for creating reconfigurable robots—metabots—capable of adapting to changing environments remains largely unexplored. Here, we report harnessing developable surface–based multistable thin-shell metastructures with high reconfigurability for adaptive manipulation and locomotion. These multistable metastructures are constructed by cutting and bonding thin polymer sheets with patterned cutouts, enabling programmable prestored elastic energy. A single unit achieves up to 20 stable configurations, while a four-unit assembly yields 256 reconfigured states, through simple folding of dynamic virtual creases. When integrated with thin sheet–based, multiresponsive soft actuators, these metastructures become highly adaptive metabots, including universal, noninvasive bistable soft grippers; magnetic multigait jumpers; and dual-responsive crawlers powered by magnetic and electroactive actuation. These systems exhibit high adaptability and maneuverability, capable of navigating complex terrains and confined environments via on-demand shape transformations, paving the way for energy-efficient, reconfigurable soft robotic platforms.
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- PAR ID:
- 10686400
- Publisher / Repository:
- American Association for the Advancement of Science
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 11
- Issue:
- 42
- ISSN:
- 2375-2548
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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