High performance electro-active artificial muscles based on 3D dendritic nickel cobalt sulfide nanorods-graphene electrodes

Abstract

As the desire for biomimicry that utilizes the advantages of natural organisms, increases, electroactive artificial muscles, an emerging technology, have been phasing-in to bioinspired applications in medicine, electronics, and soft robotics. However, it remains challenging to simultaneously obtain stable response characteristics and high bending displacement, considering the instability of electrode materials in open air environments. Here, 3D dendritic nickel cobalt sulfide nanorods grown on graphene electrodes, exhibiting stable electrochemical reactivity owing to their structural and material advantages, are employed to realize high-performance artificial muscles. Importantly, the significant influence of the phase transition of nickel-cobalt metals and graphene template in the synthesis steps on tuning the electrical and electrochemical properties is reported. The resulting artificial muscles show an almost 98 % enhanced bending performance and stable response to both AC and DC input signals without significant phase delay or distortion. These substantial improvements in the performance of artificial muscles enable the demonstration of bioinspired soft locomotive robots; these artificial muscles will thus expand the soft electronics industry in the field of next-generation human-machine interfaces.