Levine D J, Lee O A, Campbell G M, McBride M K, Kim H J, Turner K T, Hayward R C, Pikul J H
Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA.
Materials Science and Engineering, University of Colorado, Boulder, CO, 80303, USA.
Adv Mater. 2023 Nov;35(46):e2304455. doi: 10.1002/adma.202304455. Epub 2023 Oct 15.
Electroadhesive devices with dielectric films can electrically program changes in stiffness and adhesion, but require hundreds of volts and are subject to failure by dielectric breakdown. Recent work on ionoelastomer heterojunctions has enabled reversible electroadhesion with low voltages, but these materials exhibit limited force capacities and high detachment forces. It is a grand challenge to engineer electroadhesives with large force capacities and programmable detachment at low voltages (<10 V). In this work, tough ionoelastomer/metal mesh composites with low surface energies are synthesized and surface roughness is controlled to realize sub-ten-volt clutches that are small, strong, and easily detachable. Models based on fracture and contact mechanics explain how clutch compliance and surface texture affect force capacity and contact area, which is validated over different geometries and voltages. These ionoelastomer clutches outperform the best existing electroadhesive clutches by fivefold in force capacity per unit area (102 N cm ), with a 40-fold reduction in operating voltage (± 7.5 V). Finally, the ability of the ionoelastomer clutches to resist bending moments in a finger wearable and as a reversible adhesive in an adjustable phone mount is demonstrated.
带有介电薄膜的电粘附装置可以通过电编程改变刚度和粘附力,但需要数百伏电压,并且容易因介电击穿而失效。最近关于离子弹性体异质结的研究实现了低电压下的可逆电粘附,但这些材料的力容量有限且脱离力较高。设计出在低电压(<10 V)下具有大力容量和可编程脱离功能的电粘附装置是一项巨大挑战。在这项工作中,合成了具有低表面能的坚韧离子弹性体/金属网复合材料,并控制表面粗糙度以实现小型、强力且易于拆卸的亚十伏离合器。基于断裂和接触力学的模型解释了离合器柔顺性和表面纹理如何影响力容量和接触面积,并在不同几何形状和电压下得到验证。这些离子弹性体离合器在单位面积力容量(102 N/cm²)方面比现有的最佳电粘附离合器高出五倍,工作电压降低了40倍(±7.5 V)。最后,展示了离子弹性体离合器在手指可穿戴设备中抵抗弯矩的能力以及在可调节手机支架中作为可逆粘合剂的能力。