Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, CH-1700, Switzerland.
Case Western Reserve University, Cleveland, OH, 44106, USA.
Adv Mater. 2023 May;35(18):e2210409. doi: 10.1002/adma.202210409. Epub 2023 Mar 22.
Soft earthworm-like robots that exhibit mechanical compliance can, in principle, navigate through uneven terrains and constricted spaces that are inaccessible to traditional legged and wheeled robots. However, unlike the biological originals that they mimic, most of the worm-like robots reported to date contain rigid components that limit their compliance, such as electromotors or pressure-driven actuation systems. Here, a mechanically compliant worm-like robot with a fully modular body that is based on soft polymers is reported. The robot is composed of strategically assembled, electrothermally activated polymer bilayer actuators, which are based on a semicrystalline polyurethane with an exceptionally large nonlinear thermal expansion coefficient. The segments are designed on the basis of a modified Timoshenko model, and finite element analysis simulation is used to describe their performance. Upon electrical activation of the segments with basic waveform patterns, the robot can move through repeatable peristaltic locomotion on exceptionally slippery or sticky surfaces and it can be oriented in any direction. The soft body enables the robot to wriggle through openings and tunnels that are much smaller than its cross-section.
具有机械柔顺性的软蚯蚓状机器人原则上可以在传统的腿式和轮式机器人无法进入的不平坦地形和狭窄空间中导航。然而，与它们模仿的生物原型不同，迄今为止报道的大多数蚯蚓状机器人都包含限制其柔顺性的刚性组件，例如电动或压力驱动致动系统。在这里，报道了一种基于软聚合物的具有完全模块化身体的机械柔顺性蚯蚓状机器人。该机器人由经过策略组装的、电热激活的聚合物双层致动器组成，其基于具有异常大的非线性热膨胀系数的半结晶型聚氨酯。这些段基于改进的铁木辛柯模型设计，并使用有限元分析模拟来描述它们的性能。通过用基本波形模式对段进行电激活，机器人可以在非常滑或粘的表面上进行可重复的蠕动运动，并可以指向任何方向。柔软的身体使机器人能够在比其横截面小得多的开口和隧道中蠕动。
