State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing, China.
Mechatronics Research Unit, OTH Regensburg, Regensburg, Germany.
Soft Robot. 2019 Dec;6(6):701-712. doi: 10.1089/soro.2018.0120. Epub 2019 Jul 18.
Soft robotic grippers (SRGs) have been extensively employed in robotic grasping and manipulation applications due to the fact that they are beneficial for pick-and-place of difficult-to-handle and delicate objects with various geometries and stiffness in a comfortable and safer way. This article presents a bio-inspired and shape-adaptive SRG augmented with electroadhesion (EA) functionality, FinEA, by a cost-effective combination of a Fin Ray structured two-fingered SRG with two soft-stretchable EA pads. The EA pads were manufactured by screen printing a layer of electrically conductive and elastomeric carbon black powder mixed with polydimethylsiloxane onto a dielectric substrate. The compliant Fin Ray fingers, composed of soft longitudinal beams and rigid cross beams, were structurally optimized by the finite element method using ABAQUS/CAE based on three key parameters: the open angle of the longitudinal beams, the spacing between the cross beams, and the incline angle of the cross beams. The soft beams were produced by a traditional soft lithography method, whereas the rigid cross beams were three-dimensionally printed. The resultant FinEA grippers were capable of lifting not only flat/thin materials without distorting them due to the employment of EA, but also concave and convex objects due to the passively shape-adaptive Fin Ray structure and the EA functionality. In addition, the proposed FinEA grippers were able to grasp delicate materials and objects whose diameters are larger than the overall gripper length. Furthermore, 65% more weight in shear were picked up by the FinEA gripper when 4 kV was applied compared with 0 V. The FinEA concept provides useful and alternative solution for controllable adhesion-based SRGs and may facilitate the inspiration and development of future SRGs with added functionality and enhanced versatility.
软体机器人夹持器 (SRG) 由于其在舒适和安全的方式下有利于处理各种几何形状和硬度的难以处理和易碎物体的拾取和放置，因此在机器人抓取和操作应用中得到了广泛应用。本文提出了一种受生物启发的形状自适应 SRG，该夹持器通过将 Fin Ray 结构的两指 SRG 与两个柔软的可拉伸电粘附 (EA) 垫结合，具有成本效益，增加了 EA 功能，称为 FinEA。EA 垫是通过在介电基底上丝网印刷一层由导电和弹性炭黑粉末与聚二甲基硅氧烷混合制成的弹性体来制造的。顺应性的 Fin Ray 手指由软的纵向梁和刚性的横梁组成，通过基于 ABAQUS/CAE 的有限元方法进行结构优化，基于三个关键参数：纵向梁的张开角度、横梁之间的间距和横梁的倾斜角度。软梁通过传统的软光刻方法制造，而刚性横梁则通过三维打印制造。由此产生的 FinEA 夹持器不仅能够通过使用 EA 提升平坦/薄的材料而不会使其变形，而且还能够提升凹面和凸面的物体，这是由于采用了被动形状自适应的 Fin Ray 结构和 EA 功能。此外，所提出的 FinEA 夹持器能够抓取直径大于整个夹持器长度的精细材料和物体。此外，与 0V 相比，当施加 4kV 时，FinEA 夹持器可以提起 65%更多的剪切重量。FinEA 概念为基于可控粘附的 SRG 提供了有用的替代解决方案，并可能促进具有附加功能和增强通用性的未来 SRG 的灵感和发展。
