Center for Micro-BioRobotics, Istituto Italiano di Tecnologia (IIT), Viale R. Piaggio 34, 56025, Pontedera, Italy.
Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia.
Nat Commun. 2019 Jan 21;10(1):344. doi: 10.1038/s41467-018-08173-y.
Soft robots hold promise for well-matched interactions with delicate objects, humans and unstructured environments owing to their intrinsic material compliance. Movement and stiffness modulation, which is challenging yet needed for an effective demonstration, can be devised by drawing inspiration from plants. Plants use a coordinated and reversible modulation of intracellular turgor (pressure) to tune their stiffness and achieve macroscopic movements. Plant-inspired osmotic actuation was recently proposed, yet reversibility is still an open issue hampering its implementation, also in soft robotics. Here we show a reversible osmotic actuation strategy based on the electrosorption of ions on flexible porous carbon electrodes driven at low input voltages (1.3 V). We demonstrate reversible stiffening (5-fold increase) and actuation (500 deg rotation) of a tendril-like soft robot (diameter ~1 mm). Our approach highlights the potential of plant-inspired technologies for developing soft robots based on biocompatible materials and safe voltages making them appealing for prospective applications.
软机器人由于其内在的材料顺应性，有望与易碎物体、人类和非结构化环境进行良好匹配的交互。运动和刚度调节是有效的演示所需要的，但可以从植物中获得灵感来设计。植物通过协调和可逆的细胞内膨压（压力）调节来调节其刚度并实现宏观运动。最近提出了受植物启发的渗透驱动，然而，可还原性仍然是一个悬而未决的问题，阻碍了它在软机器人中的应用。在这里，我们展示了一种基于在低输入电压（1.3V）下在柔性多孔碳电极上吸附离子的可逆渗透驱动策略。我们演示了一种类似于卷须的软机器人（直径约 1mm）的可逆变硬（约 5 倍增加）和驱动（约 500 度旋转）。我们的方法突出了受植物启发的技术在开发基于生物相容性材料和安全电压的软机器人方面的潜力，使它们在未来的应用中具有吸引力。
