Design, development and locomotion control of compliant soft mobile robot

The paper presents a novel design of compliant soft mobile robot using shape memory alloy. This paper also demonstrates the capability of shape memory alloy (Ni-Ti) as an actuator for a micro robot. Soft robots provide better flexibility and softness which increases the range of locomotion and their capability in complex environment. The robot presented in the paper has 60X50X50 mm dimension. Shape memory alloy actuators were chosen because of its high power to weight ratio and gearless mechanism. The structure of the robot has two disc connected with six SMA in parallel. The four SMA used are 0.2mm diameter memorized to coil shape and the other two are 0.375mm diameter memorized to straight shape. The actuation of these two different sets of SMA with proper control were able to give an antagonistic locomotion. The locomotion was made in one direction using the method of differential friction where an additional gripper at the end was given with different adhesive material. The tension or pull force due to connecting wires of the SMA was compensated using a roller like mechanism. Hence taking benefit from the actuation of shape memory alloy, we present a novel soft robot prototype that utilizes bio-inspired antagonistic actuation for its locomotion.