Design of a Human-Inspired Sensorized and Adaptive Foot That Enhances Stability Through Tensegrity (Hi-SAFEST)

Although the evolution of mammalian feet has been extensively studied, the development of robotic feet has been slow. However, as legged robots developed, the development of adaptive and highly functional feet became important. This study introduces the Human-inspired Sensorized and Adaptive Foot that Enhances Stability through Tensegrity (Hi-SAFEST), which has high adaptability and functionality. Hi-SAFEST is consisted of artificial tendons inspired by human tendons to sense proprioception of the foot and simultaneously form a tensegrity structure mimicking the human foot structure for adaptability. Hi-SAFEST showed low moment applied to the ankle and low potential energy on various ground inclination angles and obstacles in both the simulations and experiments, which are indicating high adaptability to the surrounding environments. Functionalities were also assessed by experiments; Hi-SAFEST successfully estimated the ground inclination angle and ground reaction force using bio-inspired artificial proprioceptive tendons. In addition, Hi-SAFEST exhibited high slip resistance than conventional passive feet on both flat and rough surfaces.