Source-linked AI summary
Programming Soft Robots with Flexible Mechanical Metamaterials
Ahmad Rafsanjani, Katia Bertoldi, André R. Studart
TL;DR
Soft-robot design faces the challenge of breaking down complex functions into bioinspired architectures. The paper explores flexible metamaterials, including arranged elastic beams and reverse-engineered architectures, and concludes that their design space can enhance soft-robot performance.
Problem
A central challenge is breaking down complex functions and reverse-engineering architectures to establish bioinspired designs.
Method
The paper explores flexible metamaterials by arranging elastic beam elements and reverse-engineering architectures for bioinspired designs.
Results
Flexible metamaterials provide an ample design space for enhancing soft-robot performance.
Takeaways & Limitations
Manufacturing technologies that enable flexible metamaterials’ physical realization could support enhanced soft-robot performance.
Takeaways & Limitations
Conventional origami designs are not able to carry mechanical loads.
Abstract
from arXiv · showhide
The complex behavior of highly deformable mechanical metamaterials can substantially enhance the performance of soft robots.
Beam-based structures
Beam-based metamaterials program soft-robot deformation by arranging elastic elements to exploit bending, buckling, and snapping. Their applications span locomotion, actuation, and energy storage, but require materials that tolerate large strains without failure.
- Beam-based structures: Arranging elastic beams programs unusual mechanical behaviors in flexible metamaterials.Beam arrangements can produce diverse deformation patterns and responses.
- Beam-based structures: Negative Poisson’s ratio emerges from re-entrant beam microstructures, producing auxetic materials that thicken when stretched and thin when compressed.Auxetic and non-auxetic clutches enabled three-step inchworm locomotion with a single actuator.
- Beam-based structures: Buckling of elastic beams can trigger reversible pattern transformations, single-input soft-machine motions, and large deformations at small forces.These behaviors support soft machines and artificial muscles.
- Beam-based structures: Bistable beam snapping stores and releases elastic strain energy, enabling untethered propulsion in response to water-temperature changes.The response was demonstrated in an untethered soft robot.
- Beam-based structures: Beam-based soft-robot systems must withstand ~50% strain without breaking or fatigue failure.Large deformations are a central materials requirement for exploiting beam nonlinearities.
Perspectives
Flexible metamaterials and manufacturing advances could expand soft robots’ capabilities, while bioinspiration and AI guide designs toward functional architectures that satisfy environmental constraints. Cross-disciplinary fabrication approaches may enable flexible metamaterials to provide soft robots with unforeseen functionalities.
- Perspectives: Flexible metamaterials offer a broad design space for enhancing soft-robot performance, provided manufacturing technologies can physically realize their architectures.The proposed direction combines design exploration with fabrication methods capable of producing flexible metamaterials.
- Perspectives: A library of functional metamaterial modules could enable robots to morph, interact safely, perform logic, sense, and adapt in unstructured environments.The architectures would be assembled by identifying and piecing together functional modules from a large design library.
- Perspectives: Bioinspired design must decompose evolved functions and reverse-engineer architectures that perform desired tasks under environmental boundary conditions.This top-down approach uses designs perfected through natural evolution as sources for targeted functions.
- Perspectives: AI can guide bottom-up searches for metamaterial designs suited to complex end functions, after which advanced manufacturing must realize the selected architectures.Multimaterial soft-material 3D printing and directed assembly are identified as promising responses to the fabrication challenge.
- Perspectives: Cross-disciplinary work spanning materials science, mechanical engineering, AI, and robotics could soon give soft robots unforeseen functionalities through flexible metamaterials.The perspective explicitly links these disciplines to future robotic capabilities.