Manufacturing the Next-Generation of Soft Robotics with Ultra-Efficient, Strong, Electro-Mechanical Artificial Muscles

随着人类开始更多地与机器人互动，我们将需要各种形状的适应性机器：与人并肩工作的制造机器人，从受伤中恢复的可穿戴设备，增强人类能力的智能假肢等。在这些截然不同的领域，最紧迫的挑战是找到人造肌肉或软致动器，为这些设备提供动力。该领域过去的方法由于操作复杂（例如，流体执行器需要由泵驱动，并由阀门控制），响应速度慢（例如，离子聚合物-金属复合材料的扩散有限，使其比天然肌肉慢得多）和低能量效率（例如，在形状记忆合金中，大部分输入电能作为热量损失到环境中，而不是用于触发相变）而具有局限性。拟议的研究计划将开发基于介电弹性体致动器（dea）的下一代人造肌肉，当两个可拉伸电极之间施加电场时，柔性电容器会发生机械变形。与其他技术相比，dea是柔软的（对于没有框架的多层dea），仅由电气输入驱动，并且像大多数天然肌肉一样强壮和快速。拟议的研究项目借用了我以前专业领域的概念，包括电化学、材料科学和折纸结构。dea通常是从机械角度来描述的，评估不同驱动频率下的力输出和位移，而不评估相应的电气特性。我的研究小组将研究dea在驱动过程中的电学行为，类似于电池如何通过重复的充电/放电循环来表征。使用这种方法，我们将对dea长期行为中电气和机械应力之间的相互作用有一个前所未有的了解。同样，DEA失效通常归因于弹性体的行为，而没有仔细检查电极或弹性体-电极界面。利用超薄电极和新颖的表征技术，我们将把材料微观结构与器件性能联系起来。最后，dea通常在一个相对刚性的框架内操作，这限制了运动范围，使机器人集成具有挑战性。通过扩展新的二维制造技术，我的团队将为下一代软机器人构建具有嵌入式执行器的复合结构。该研究项目植根于机械工程，使用新颖的工具和工艺为人造肌肉的制造、评估和集成到智能设备和机器人中设定了新的标准。完成后，该项目将应用于人类和机器人互动的一系列领域，包括协同制造、假肢、触觉通信设备等。

As humans start to interact more with robots, we will require adaptable machines in a variety of shapes: manufacturing robots to work side-by-side with people, wearable devices to rehabilitate from injury, smart prosthetics to augment human capability, etc. Across these vastly different areas, the most pressing challenge has to find the artificial muscles, or soft actuators, to power these devices. Past approaches in the field have limitations due to complex operation (e.g., fluidic actuators need to be driven by pumps, and directed by valves), slow response speed (e.g., ionic polymer-metal composites are diffusion limited, making them significant slower than natural muscles), and low energy efficiency (e.g., in a shape memory alloy most of the input electrical energy is lost as heat to the environment, and not used to trigger the phase change). The proposed research program will develop the next generation of artificial muscles, based on dielectric elastomer actuators (DEAs), compliant capacitors that undergo mechanical deformation when an electric field is applied between two stretchable electrodes. Compared to other technologies, DEAs are soft (for multilayer DEAs without a frame), driven by only an electrical input, and as strong and fast as most natural muscles. The proposed research programs borrows concepts from areas in which I have previous expertise, including electrochemistry, materials science, and folding origami structures. DEAs are most often characterized from a mechanical standpoint, evaluating the force output and displacement, at different actuation frequencies, without evaluating the corresponding electrical properties. My research group will study the electrical behavior of DEAs during actuation, similar to how batteries are characterized by repeated charge / discharge cycles. Using this approach we will have an unprecedented look at the interplay between electrical and mechanical stress in the long term behavior of DEAs. Similarly, DEA failure is generally attributed to the behavior of the elastomer, without close examination of the electrode or the elastomer-electrode interface. With ultra-thin electrodes and novel characterization techniques, we will link material microstructure to device performance. Lastly, DEAs are often operated within a relatively rigid frame, which limits the range of motion and makes robot integration challenging. By expanding upon novel 2D fabrication techniques, my group will build composite structures with embedded actuators for the next generation of soft robotics. The research program is rooted in Mechanical Engineering, using novel tools and processes to set new standards for how artificial muscles are manufactured, evaluated, and integrated into smart devices and robotics. When completed, the program will find applications in a range of fields where humans and robots interact, including collaborative manufacturing, artificial limbs, tactile communication devices, and beyond.