刚性机器人在重复性任务中能够做到精确，但在非结构化环境中却面临困难。大自然在这些环境中的多功能性启发了研究人员开发仿生机器人，这类机器人结合了柔顺且可收缩的人工肌肉。在最近提出的人工肌肉技术中，电液驱动器极具前景，因为它们在速度和功率密度方面提供了与哺乳动物肌肉相当的性能。然而，它们需要高驱动电压，并且由于暴露的电极而存在安全隐患。这些高电压导致驱动电子设备要么体积庞大，要么效率低下，使得无缆、高自由度的仿生机器人难以实现。在此，我们提出了液压放大低压静电（HALVE）驱动器，在仅1100 V的驱动电压下，其平均功率密度（50.5 W kg-1）和峰值应变速率（971 % s-1）可与哺乳动物骨骼肌相媲美。与使用顺电介质的其它电液驱动器相比，该驱动电压大约低5-7倍。此外，HALVE驱动器触摸安全、防水且具有自清除功能，使其易于在可穿戴设备和机器人中实施。我们对该驱动器的关键性能指标进行了表征、建模和物理验证，并将其性能与最先进的电液设计进行了比较。最后，我们在两种基于肌肉的电液机器人上展示了我们驱动器的实用性：一个无缆软体机器人游泳器和一个机器人夹爪。我们预见到HALVE驱动器可以成为未来高度仿生无缆机器人和具有许多独立人工肌肉（如仿生手、面部或外骨骼）的可穿戴设备的关键构建模块。
英文摘要：
Rigid robots can be precise in repetitive tasks, but struggle in unstructured environments. Nature's versatility in such environments inspires researchers to develop biomimetic robots that incorporate compliant and contracting artificial muscles. Among the recently proposed artificial muscle technologies, electrohydraulic actuators are promising since they offer performance comparable to that of mammalian muscles in terms of speed and power density. However, they require high driving voltages and have safety concerns due to exposed electrodes. These high voltages lead to either bulky or inefficient driving electronics that make untethered, high-degree-of-freedom bio-inspired robots difficult to realize. Here, we present hydraulically amplified low voltage electrostatic (HALVE) actuators that match mammalian skeletal muscles in average power density (50.5 W kg-1) and peak strain rate (971 % s-1) at a driving voltage of just 1100 V. This driving voltage is approx. 5-7 times lower compared to other electrohydraulic actuators using paraelectric dielectrics. Furthermore, HALVE actuators are safe to touch, waterproof, and self-clearing, which makes them easy to implement in wearables and robotics. We characterize, model, and physically validate key performance metrics of the actuator and compare its performance to state-of-the-art electrohydraulic designs. Finally, we demonstrate the utility of our actuators on two muscle-based electrohydraulic robots: an untethered soft robotic swimmer and a robotic gripper. We foresee that HALVE actuators can become a key building block for future highly-biomimetic untethered robots and wearables with many independent artificial muscles such as biomimetic hands, faces, or exoskeletons.
ETH Zurich（苏黎世联邦理工学院）；California Institute of Technology（加州理工学院）
In most macro-scale robotics systems , propulsion and controls are enabled through a physical tether or complex on-board electronics and batteries. A tether simplifies the design process but limits the range of motion of the robot, while on-board controls and power supplies are heavy and complicate the design process. Here we present a simple design principle for an untethered, entirely soft, swimming robot with the ability to achieve preprogrammed, directional propulsion without a battery or on-board electronics. Locomotion is achieved by employing actuators that harness the large displacemen…
Computational Design and Fabrication of Modular Robots with Untethered Control
Institute of Science and Technology Austria（奥地利科学与技术研究所）；University of Tsukuba（茨口大学）；Cluster Metaverse Lab（元宇宙集群实验室）；ETH Zurich（苏黎世联邦理工学院）；California Institute of Technology（加州理工学院）；The University of Osaka（大阪大学）
A Robotic Testing Platform for Pipelined Discovery of Resilient Soft Actuators
Department of Mechanical and Industrial Engineering, University of Toronto（多伦多大学机械与工业工程系）；Institute of Materials Science, University of Connecticut（康涅狄格大学材料科学研究所）；School of Mechanical, Aerospace, and Manufacturing Engineering, University of Connecticut（康涅狄格大学机械、航空航天与制造工程学院）；Material Science and Engineering, University of Connecticut（康涅狄格大学材料科学与工程系）；Inorganic Polymers Department, Petru Poni Institute of Macromolecular Chemistry（彼得·波尼宏分子化学研究所无机聚合物部门）
Portable, High-Frequency, and High-Voltage Control Circuits for Untethered Miniature Robots Driven by Dielectric Elastomer Actuators
Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment, Beijing Key Laboratory of Transformative High-end Manufacturing Equipment and Technology, Tsinghua University（机械工程系、先进设备摩擦学国家重点实验室、北京 transformative 高端制造装备与技术重点实验室、清华大学）
University of Colorado（科罗拉多大学）；Materials Science and Engineering Program, University of Colorado（科罗拉多大学材料科学与工程项目）；Department of Electrical Engineering, University of Colorado（科罗拉多大学电气工程系）；Department of Computer Science, University of Colorado（科罗拉多大学计算机科学系）
Soft robotics is a field of robotic system design characterized by materials and structures that exhibit large-scale deformation, high compliance, and rich multifunctionality. The incorporation of soft and deformable structures endows soft robotic systems with the compliance and resiliency that makes them well-adapted for unstructured and dynamic environments. While actuation mechanisms for soft robots vary widely, soft electrostatic transducers such as dielectric elastomer actuators (DEAs) and hydraulically amplified self-healing electrostatic (HASEL) actuators have demonstrated promise due t…
Boston University（波士顿大学）；Carnegie Mellon University（卡内基梅隆大学）
Untethered soft robots that locomote using electrothermally-responsive materials like shape memory alloy (SMA) face challenging design constraints for sensing actuator states. At the same time, modeling of actuator behaviors faces steep challenges, even with available sensor data, due to complex electrical-thermal-mechanical interactions and hysteresis. This article proposes a framework for in-situ sensing and dynamics modeling of actuator states, particularly temperature of SMA wires, which is used to predict robot motions. A planar soft limb is developed, actuated by a pair of SMA coils, tha…
We present formulation and open-source tools to achieve in-material model predictive control of sensor/actuator systems using learned forward kinematics and on-device computation. Microcontroller units (MCUs) that compute the prediction and control task while colocated with the sensors and actuators enable in-material untethered behaviors. In this approach, small parameter size neural network models learn forward kinematics offline. Our open-source compiler, nn4mc, generates code to offload these predictions onto MCUs. A Newton-Raphson solver then computes the control input in real time. We fi…
The demining of landmines using drones is challenging; air-releasable payloads are typically non-intelligent (e.g., water balloons or explosives) and deploying them at even low altitudes (~6 meter) is inherently inaccurate due to complex deployment trajectories and constrained visual awareness by the drone pilot. Soft robotics offers a unique approach for aerial demining, namely due to the robust, low-cost, and lightweight designs of soft robots. Instead of non-intelligent payloads, here, we propose the use of air-releasable soft robots for demining. We developed a full system consisting of an…
Cuttlebot: a platform demonstration for complex, autonomous, bio-inspired swimmers
School of Mechanical, Aerospace, and Manufacturing Engineering, University of Connecticut（康涅狄格大学机械、航空航天与制造工程学院）；Department of Mechanical and Industrial Engineering, University of Toronto（多伦多大学机械与工业工程系）；University of Connecticut, Institute of Materials Science（康涅狄格大学材料科学研究所）；Department of Mechanical and Aerospace Engineering, Princeton University（普林斯顿大学机械与航空航天工程系）
