V2O5 nanofibre sheet actuators

Vanadium oxides, such as V 2 O 5 , are promising for lithium-ion batteries 1 , 2 , catalysis 3 , electrochromic devices 4 , 5 and sensors 6 , 7 . Vanadium oxides were proposed more than a decade ago for another redox-dependent application: the direct conversion of electrical energy to mechanical energy in actuators (artificial muscles) 8 . Although related conducting polymer 8 , 9 and carbon nanotube actuators 10 have been demonstrated, electromechanical actuators based on vanadium oxides have not be realized. V 2 O 5 nanofibres 6 , 11 and nanotubes 12 provide the potential advantages of low-cost synthesis by sol–gel routes and high charging capacity and long cycle life 13 , 14 . Here, we demonstrate electromechanical actuation for obtained high modulus V 2 O 5 sheets comprising entangled V 2 O 5 nanofibres. The high surface area of these V 2 O 5 sheets facilitates electrochemical charge injection and intercalation that causes the electromechanical actuation. We show that the V 2 O 5 sheets provide high Young's modulus, high actuator-generated stress, and high actuator stroke at low applied voltage.