Polyaniline/Reduced Graphene Oxide/Carbon Nanotube Composites for Actuation-Based Sensing for Energy Storage

Until now, many carbon-based soft actuators with excellent performance have been developed, and various indicators of actuators are close to the limit. However, compared with the intelligence and versatility of natural biological muscles, soft actuators still have the shortcomings of single function and insufficient intelligence. Herein, polyaniline/reduced graphene oxide/carbon nanotube (PANI/RGO/CNT) composites are fully used to design and fabricate a smart gripper with a self-powered temperature-sensing function. First of all, the PANI/RGO/CNT composites have the characteristics of low coefficient of thermal expansion (CTE) and negative temperature resistivity. By cooperating with polymers with high CTE, a multifunctional bilayer actuator with a temperature-sensing function can be constructed with a temperature coefficient of resistance of 2364 ppm K^–1. With the light irradiation (power density of 300 mW cm^–2), the surface temperature, bending curvature, and resistance change of the actuator are as high as 48.8 °C, 0.86 cm^–1, and −6.1%, respectively. Second, the PANI/RGO/CNT composite also possesses the advantage of large-area capacitance (165.8 mF cm^–2). Thus, an integrated bilayer actuator with energy storage modules can be constructed through clever structural design and used as deformable supercapacitors. Finally, based on the similarity in structure and actuation mechanism of the multifunctional bilayer actuator and the integrated bilayer actuator, a smart gripper with a self-powered temperature-sensing function is proposed to provide real-time feedback of the change in temperature of the smart gripper as it grasps the object. The versatility of the smart gripper is achieved without increasing the complexity of the structure, demonstrating the advantages of the design concept of integrating sensing and energy storage in the design of soft actuators. The proposed PANI/RGO/CNT composites have great potential to be used in the fields of intelligent actuators, deformable supercapacitors, and artificial muscles.