Mechanisms of Genipin and MCNT effects on the actuation properties and failure of chitosan gel bionic artificial muscles

The poor actuation characteristics of current bionic artificial muscles limit their application in engineering practice. Chitosan and graphene are used as the main components to prepare bionic artificial muscles. The driving characteristic indexes of the bionic artificial muscles are proposed, including the output force, output displacement and the respective response speed, and the test platform is built. The mechanism of the influence of Multi-walled carbon nanotubes (MCNT) and Genipin on the actuation characteristics of the bionic artificial muscles is investigated. MCNT crosslinked with graphene enhances the electrical conductivity of the electrode layer, while Genipin crosslinked with chitosan improves the flexibility of the artificial muscles themselves. The bionic artificial muscle with co-addition of Genipin and MCNT showed improvement in output displacement, output force, and response speed. The failure mechanism of the bionic artificial muscle and the improvement mechanism of the additives were analyzed by both electron microscopy and water loss rate, and the changes in the microscopic surface of the electrode layer and the driving layer as well as the dissipation of the internal water were the main reasons for the failure.MCNT and Genipin improved the driving characteristics by enhancing the electrode capacity and accelerating the ion migration rate, respectively.