Constant development of soft robots, stretchable electronics, or flexible medical devices forces the research to look for new flexible structures that can change their shapes under external physical stimuli. This study presents a soft robotic structure that can change its shape into different three-dimensional (3D) configurations in response to electric current flown through the embedded liquid-metal conductors enabling electromagnetic actuation. The proposed structure is composed of volumetric pixels (voxels) connected in series where each can be independently controlled by the inputs of electrical current and vacuum pressure. A single voxel is made up of a granular core (GC) with an outer shell made of silicone rubber. The shell has embedded channels filled with liquid metal. The structure changes its shape under the Lorentz force produced by the liquid metal channel under applied electrical current. The GC allows the structure to maintain its shape after deformation even when the current is shut off. This is possible due to the granular jamming effect. In this study, we show the concept, the results of multiphysics simulation, and experimental characterization, including among other techniques, such as 3D digital image correlation or 3D magnetic field scanning, to study the different properties of the structure. We prove that the proposed structure can morph into many different shapes with the amplitude higher than 10 mm, and this process can be both fully reversible and repeatable.

中文翻译：

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使用液态金属电磁致动器的可编程变形软机器人结构。


软机器人、可伸缩电子设备或柔性医疗设备的不断发展迫使研究寻找可以在外部物理刺激下改变形状的新型柔性结构。本研究提出了一种软机器人结构，它可以响应流经嵌入式液态金属导体的电流，将其形状改变为不同的三维 （3D） 配置，从而实现电磁驱动。所提出的结构由串联的体积像素 （voxel） 组成，其中每个像素都可以由电流和真空压力的输入独立控制。单个体素由颗粒状核心 （GC） 和硅橡胶制成的外壳组成。外壳具有填充液态金属的嵌入式通道。该结构在施加电流下液态金属通道产生的洛伦兹力下改变其形状。GC 允许结构在变形后保持其形状，即使电流关闭也是如此。这是由于颗粒干扰效果而可能的。在本研究中，我们展示了概念、多物理场仿真的结果和实验表征，包括 3D 数字图像相关或 3D 磁场扫描等其他技术，以研究结构的不同特性。我们证明，所提出的结构可以变形成许多振幅高于 10 mm 的不同形状，并且这个过程既可以是完全可逆的，也可以是可重复的。