Interface electrode and enhanced actuation performance of SiO2-GO/PFSA-based IPMC soft actuators

In this study, ‘three-dimensional structure’ nanohybrid particle (SiO₂-GO) were synthesized by in situ hydrolysis and composited with perfluorosulfonic acid (PFSA) to increase the water uptake (WUP) and ion exchange capacity (IEC) of the cast membranes. Ionic polymer metal composite (IPMC) soft actuators were fabricated based on the cast pure PFSA, GO/PFSA and SiO₂-GO/PFSA membranes. The morphology and properties of IPMC were researched, and the relationship between them was analyzed in this article. The mechanism of SiO₂-GO particles enhancing the properties of IPMC was revealed. The effects of incorporating GO and SiO₂-GO on IPMC actuators were analyzed using physicochemical and electromechanical measurements comparing with the corresponding behavior of pure PFSA-based IPMC actuators. Morphology of IPMC showed effective incorporation of GO and SiO₂-GO and clarified the dependency of Pt interface electrode on the SiO₂-GO content of the PFSA membranes. The addition of SiO₂-GO increased dramatically the WUP and IEC of the PFSA membranes and autuation performance of the IPMC actuators. The IPMC with 1 wt% SiO₂-GO showed superb properties. The displacement of 1 wt% SiO₂-GO under 3 V AC voltage reached 28.4 mm, which is 3.2 times higher than that of the pure PFSA. The maximum displacement under DC voltage reached 44.7 mm (5.5 V), and the blocking force reached 43.2 mN (5 V), which increased respectively 1.1 times and two times.