Within the field of robotics, stiffness tuning technologies have potential for a variety of applications—perhaps most notably for robotic grasping. Many stiffness tuning grippers have been developed that can grasp fragile or irregularly shaped objects without causing damage and while still accommodating large loads. In addition to limiting gripper deformation when lifting an object, increasing gripper stiffness after contact formation improves load sharing at the interface and enhances adhesion. In this study, we present a novel stiffness and adhesion tuning gripper, enabled by the thermally induced phase change of a thermoplastic composite material embedded within a silicone contact pad. The gripper operates by bringing the pad into contact with an object while in its heated, soft state, and then allowing the pad to cool and stiffen to form a strong adhesive bond before lifting the object. Pull-off tests conducted using the gripper show that transitioning from a soft to stiff state during grasping enables up to 6 × increase in adhesion strength. Additionally, a finite element model is developed to simulate the behavior of the gripper. Finally, pick-and-place demonstrations are performed, which highlight the gripper's ability to delicately grasp objects of various shapes, sizes, and weights.

中文翻译：

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通过热塑性复合材料调整刚度和附着力，实现多功能软机器人夹持器

在机器人领域，刚度调整技术具有多种应用潜力——也许最显着的是机器人抓取。已经开发了许多刚度调整夹具，它们可以抓取易碎或形状不规则的物体，而不会造成损坏，同时仍能承受大负载。除了在提升物体时限制夹具变形外，在接触形成后增加夹具刚度可改善界面处的负载分配并增强附着力。在这项研究中，我们提出了一种新的刚度和附着力调节夹具​​，它是通过嵌入硅胶接触垫内的热塑性复合材料的热诱导相变实现的。夹持器通过在加热、柔软状态下使垫与物体接触来操作，然后在抬起物体之前让垫子冷却并变硬以形成牢固的粘合力。使用夹具进行的拉断测试表明，在抓取过程中从柔软状态转变为坚硬状态可以使粘合强度提高 6 倍。此外，还开发了一个有限元模型来模拟夹具的行为。最后，进行了取放演示，突出了抓手精细抓取各种形状、大小和重量的物体的能力。