Natural Cellulose-Full-Hydrogels Bioinspired Electroactive Artificial Muscles: Highly Conductive Ionic Transportation Channels and Ultrafast Electromechanical Response

The design of smart full-hydrogel actuators constructed with natural carbohydrate polymers applied in biomedical and tissue engineering is very important but challenging. Herein, inspired by the efficient transportation of nerve impulses from human muscle, a very simple and natural enhancement strategy was proposed for the preparation of high-efficiency ion transportation channels and high-performance cellulose-all-hydrogel electroactive human-like muscles. Simulating the mechanisms that nerve excitation in human muscle are transmitted through, e.g., releasing ions into efficient channels, co-doped conductive nanoparticles of manganese dioxide (MnO2)/polyaniline/multi-walled carbon nanotubes (MWCNTs)/reduced graphene oxide (r-GOx) are applied to construct ionic electrolyte membrane (IEM) with superconductive ion channels based on a natural cellulose polymer as a skeleton template, and the obtained product demonstrated outstanding ion transportation efficiency, mechanical properties and electrochemical properties. Bioinspired artificial muscles prepared by IEM exhibit excellent actuation performance including superfast response speed, deflection displacement (16.284 mm), and output force (4.153 mN). These advantages are largely attributed to the superconductive ion channels formed by the codoping of conductive nanoparticles, and this anisotropic feature also contributes to the increase in porosity and specific surface area within the IEM. This study reveals that the bioinspired idea of developing efficient ion transportation channels provides an innovative inspiration for accelerating the actuation performance of artificial muscles.