Wireless Capacitive Measurement Board for Wearable or Proprioceptive Applications

Despite widespread capacitance-based proprioception in soft and wearable robots, few measurement tools are "plug-and-play," compact, and operate wirelessly. We present a capacitive to digital measurement board with a footprint of less than 900 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and sub-6 g weight that may be untethered or transmit data via ROS publisher node. We characterize the board’s accuracy, noise performance, and ability to reject electromagnetic interference and found a factor of 3 improvement over an unshielded board. We demonstrated the board in two applications: a sensing sleeve that tracks biceps muscle activation, with a capacitance range of 10 pF, and measuring the proprioception of a soft origami robot with a capacitance change of 0.4 pF, both with a sampling rate of 18 Hz.