Electroadhesion has shown the potential to deliver versatile handling devices because of its simplicity of actuation and rapid response. Current electroadhesion systems have, however, significant difficulties in adapting to external objects with complex shapes. Here, a novel concept of metasurface is proposed by combining the use of natural fibers (flax) and shape memory epoxy polymers in a hygromorphic and thermally actuated composite (HyTemC). The biobased material composite can be used to manipulate adhesive surfaces with high precision and controlled environmental actuation. The HyTemC concept is preprogrammed to store controllable moisture and autonomous desorption when exposed to the operational environment, and can reach predesigned bending curvatures up to 31.9 m-1 for concave and 29.6 m-1 for convex shapes. The actuated adhesive surface shapes are generated via the architected metasurface structure, incorporating an electroadhesive component integrated with the programmable biobased materials. This biobased metasurface stimulated by the external environment provides a large taxonomy of shapes from flat, circular, single/double concave, and wavy, to piecewise, polynomial, trigonometric, and airfoil configurations. The objects handled by the biobased metasurface can be fragile because of the high conformal matching between contacting surfaces and the absence of compressive adhesion. These natural fiber-based and environmentally friendly electroadhesive metasurfaces can significantly improve the design of programmable object handling technologies, and also provide a sustainable route to lower the carbon and emission footprint of smart structures and robotics.
Bibliographical noteFunding Information:
Q.L. is grateful for the support of the Faculty of Engineering of the University of Bristol. F.S. acknowledges the logistical support of the H2020 BBI SSUCHY project for the use of the flax fibers and the composite manufacturing facilities. F.S. also acknowledges the support of the ERC-2020-AdG 101020715 NEUROMETA project. J.R. is funded by the EPSRC through grants EP/V062158/1, EP/T020792/1, EP/V026518/1, EP/S026096/1, and EP/R02961X/1 and the Royal Academy of Engineering as Chair of Emerging Technologies. J.G. appreciates the Scientific Research Foundation for New Faculties at Harbin Institute of Technology (Shenzhen) (20200198), the Scientific Research Foundation for High-level Talents at Shenzhen (ZX20210144), and the National Natural Science Foundation of China (grant no. 12102106).
© 2022 The Authors. Published by American Chemical Society.
- natural fibers
- shape morphing