Development of Compact Flexible Displacement Sensors Using Ultrasonic Sensor for Wearable ActuatorsTetsuya Akagi, Shujiro Dohta, Takafumi Morimoto, Yasuko Matsui and So ShimookaMATEC Web of Conferences, 51 (2016) 02002DOI: https://doi.org/10.1051/matecconf/20165102002