Twisted-and-Coiled Actuators with Free Strokes Enable Soft Robots with Programmable Motions
Twisted-and-Coiled Actuators with Free Strokes Enable Soft Robots with Programmable Motions
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DOI：
10.1089/soro.2019.0175
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发表时间：
2020-06-22
期刊：
影响因子：
7.9
通讯作者：
Zhao, Jianguo
中科院分区：
文献类型：
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作者：
Sun, Jiefeng;Tighe, Brandon;Zhao, Jianguo
各种驱动器（例如，气动，电缆，介电弹性体等）已被用于驱动软机器人。除了广泛使用的致动器外，一种相对较新的人造肌肉-扭曲和卷曲致动器(TCAs)-有望用于驱动厘米级软机器人，因为它们成本低，工作密度大，并且可以由电力驱动。然而，现有的tca驱动的软体机器人一般只能产生简单的弯曲运动。原因是用传统方法制造的tca必须预加载以产生大的收缩，因此不能正确地驱动软机器人。在这项工作中，提出了一种升级技术来制造可以提供48%自由冲程（无预压收缩）的tca。我们首先比较了自由行程TCAs与传统TCAs的静态性能，然后表征了制造参数如何影响TCAs的行程和受力能力。之后，我们证明了这种tca可以驱动具有可编程运动（抓握，扭转和三维弯曲）的厘米级软机器人。最后，我们结合这些动作来展示一个可以执行拾取任务的柔性机械臂。我们期望具有自由笔划的tca可以使微型软机器人具有丰富的三维运动，用于运动和操作。由于tca是电力驱动的，我们也可以通过携带车载电池和控制电路来开发无系绳软机器人。
Various actuators (e.g., pneumatics, cables, dielectric elastomers, etc.) have been utilized to actuate soft robots. Besides widely used actuators, a relatively new artificial muscle-twisted-and-coiled actuators (TCAs)-is promising for actuating centimeter-scale soft robots because they are low cost, have a large work density, and can be driven by electricity. However, existing works on TCA-actuated soft robots in general can only generate simple bending motion. The reason is that TCAs fabricated with conventional methods have to be preloaded to generate a large contraction, and thus cannot actuate soft robots properly. In this work, an upgraded technique is presented to fabricate TCAs that can deliver 48% free strokes (contraction without preloading). We first compare the static performance of TCAs with free strokes with conventional TCAs, and then characterize how will the fabrication parameters influence the TCAs' stroke and force capability. After that, we demonstrate that such TCAs can actuate centimeter-scale soft robots with programmable motions (gripping, twisting, and three-dimensional bending). Finally, we combine those motions to demonstrate a soft robotic arm that can perform a pick-and-place task. We expect that TCAs with free strokes can enable miniature soft robots with rich three-dimensional motions for both locomotion and manipulation. Because TCAs are electrically driven, we can also potentially develop untethered soft robots by carrying onboard batteries and control circuits.