Robotics Institute, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA.
Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA.
Adv Sci (Weinh). 2022 Sep;9(26):e2201963. doi: 10.1002/advs.202201963. Epub 2022 Jul 21.
Progress in artificial muscles relies on new architectures that combine soft matter with transduction mechanisms for converting controlled stimuli into mechanical work. Liquid metal, in particular eutectic gallium-indium (EGaIn), is promising for creating an artificial muscle since it is intrinsically deformable and capable of generating significant force and shape change through low voltage stimulation. In this work, a muscle-inspired structure for designing liquid metal actuators is presented, where EGaIn droplets are configured with copper pads to linearly contract. By theory and experiments, it is demonstrated that this design enables higher work densities and stress, making it a favorable actuator at smaller length scales. Furthermore, higher frequency (up to 5 Hz) operation is achieved by prestretching an antagonistic pair of actuators, where energy bistability enables fast-switching actuation. Overall, this muscle-inspired architecture shows a unique combination of low voltage operation, higher energy density at smaller scales, structural scalability, and higher frequency actuation.
人工肌肉的进展依赖于新的架构，这些架构将软物质与转换机制结合在一起，将受控刺激转化为机械功。液态金属，特别是共晶镓铟（EGaIn），是一种很有前途的人工肌肉材料，因为它本质上是可变形的，并且能够通过低电压刺激产生显著的力和形状变化。在这项工作中，提出了一种受肌肉启发的设计液态金属致动器的结构，其中 EGaIn 液滴与铜片配置以实现线性收缩。通过理论和实验，证明了这种设计可以提高工作密度和应力，使其成为在较小尺寸下更有利的致动器。此外，通过预拉伸一对拮抗的致动器，可以实现更高的频率（高达 5 Hz）操作，其中能量双稳态使快速切换致动成为可能。总的来说，这种受肌肉启发的架构展示了低电压操作、较小尺寸下更高的能量密度、结构可扩展性和更高频率致动的独特组合。
