Design of a soft bionic elbow exoskeleton based on shape memory alloy spring actuators

Abstract. Shape memory alloy (SMA) is a kind of active deformation material with self-sensing and driving ability. It very similar to the performance human muscles, through temperature changes produce phase output force displacement, it has ability restore initial shape size. The combination SMA wearable robotic technology advantages being light weight, energy-saving, having great human–exoskeleton interaction. However, existing flexible exoskeletons driven by are only designed bionic primary ignoring role antagonistic muscles. This study presents novel soft elbow exoskeleton based on spring actuators (Sobee-SMA). adopts design, combining high-elastic-material rubber band simulate contraction relaxation skeletal Through pulse width modulation (PWM) experiment, voltage selected as 12 V, PWM duty cycle 90 % during heating, 18 heat preservation. In relaxed state healthy subjects, range motion about 0–80?, maximum 60–70 ?C. During circular movement elbow, can be maintained within operating without high temperature. conclusion, provides elbow-assisted ensures safety heating process.