Soft actuator for hand rehabilitation

As we all know, rigid structure is the universal form of robots. They can be controlled accurately, but are not suitable enough for applying in rehabilitation, especially for hands. Human´s hands have some complicated patterns of movement and narrow joint range of motion, so rigid accessory equipment may cause secondary injury. For the purpose of avoiding this potential risk, the idea of applying soft structure to hand rehabilitation robot is presented in this paper. The soft robot is a new research direction in the field of robot industry, especially in rehabilitation. The soft actuator we presented is made of liquid silicone and thread, and can be tied to the back of human´s hands. When it is inflated or deflated, a bending and stretching motion of hands follow with the deformation of soft actuators. It works by deforming repeatedly. The soft actuator has some advantages such as portable, lightweight, low-cost, safe, low-impedance and so on. It works well by the cooperation of vacuum pump which can provide incessant air and solenoid valve which is used for reversing. In the whole system, force sensing resistor and bending sensor are used in the experiments. In order to prove that the soft actuator can work smoothly, we had a test to explore the relationship between air inflow and bending angle. The result that their relationship is close to a straight line means controlling easily and working well. Beacons of these advantages the soft robots have, a wide application prospect in rehabilitation or other fields is available.