The need for compliant and proprioceptive actuators has grown more evident in pursuing more adaptable and versatile robotic systems. Hydraulically Amplified Self-Healing Electrostatic (HASEL) actuators offer distinctive advantages with their inherent softness and flexibility, making them promising candidates for various robotic tasks, including delicate interactions with humans and animals, biomimetic locomotion, prosthetics, and exoskeletons. This has resulted in a growing interest in the capacitive self-sensing capabilities of HASEL actuators to create miniature displacement estimation circuitry that does not require external sensors. However, achieving HASEL self-sensing for actuation frequencies above 1 Hz and with miniature high-voltage power supplies has remained limited. In this paper, we introduce the F-HASEL actuator, which adds an additional electrode pair used exclusively for capacitive sensing to a Peano-HASEL actuator. We demonstrate displacement estimation of the F-HASEL during high-frequency actuation up to 20 Hz and during external loading using miniaturized circuitry comprised of low-cost off-the-shelf components and a miniature high-voltage power supply. Finally, we propose a circuitry to estimate the displacement of multiple F-HASELs and demonstrate it in a wearable application to track joint rotations of a virtual reality user in real-time.

翻译：在追求更具适应性和多功能的机器人系统的过程中，对柔性且具备本体感知能力的致动器的需求日益凸显。液压放大自愈静电（HASEL）致动器凭借其固有的柔软性和灵活性展现出独特优势，使其成为多种机器人任务的理想候选方案，包括与人类和动物的精细交互、仿生运动、假肢及外骨骼等。这引发了人们对利用HASEL致动器的电容自感知能力来开发微型位移估计电路的兴趣——此类电路无需外部传感器。然而，在高于1 Hz的驱动频率下实现HASEL自感知，并配合微型高压电源，仍面临诸多限制。本文介绍了F-HASEL致动器，它在Peano-HASEL致动器的基础上增加了一个专用于电容传感的额外电极对。我们展示了F-HASEL在高达20 Hz的高频驱动及外部负载条件下，利用由低成本商用元件和微型高压电源构成的微型电路实现位移估计的能力。最后，我们提出了一种用于估计多个F-HASEL位移的电路，并在可穿戴应用中演示了其实时追踪虚拟现实用户关节旋转的功能。