Design of Carbon Fiber Based Flexible Soft Heater for SMP Embedded Soft Actuators: A Step Towards Artificial Joints

Shape memory polymer is smart material of navel class, having properties of dramatically modulate its elasticity upon external stimuli such as heating. Recently, Shape memory polymer (SMP) are successfully integrated with soft robotics for resolving compliance complexities associated with them such as poor stiffness or low payload capability. However, heating of thermally responsive SMP is always been challenging for robotics application. Therefore, in this paper we have proposed a novel design of heater based on Joule heating method. The proposed heater is soft, flexible, strong and powerful to generate heat up to several degrees at lower voltages. Besides that, different experiments have been performed to investigate the repeatability and heating performance of the proposed design. Results from the electrically actuated shape recovery test have shown that the proposed heater can uniformly heat 1.5mm thick SMP sheet and perform quick shape recovery within 30 seconds at 12V. Finally, to demonstrate the practical application of our proposed design, we have fabricated a soft robotic finger and introduced the concept of artificial joints by combining SMP substrate with attached heaters to a soft pneumatic finger and achieved different bending motions by activating different sets of joints.