Charge-induced asymmetrical displacement of an aligned carbon nanotube buckypaper actuator

Randomly dispersed carbon nanotube buckypaper (BP) actuation in open air, ambient conditions was shown to correlates well with the carbon–carbon bond length changes due to charge and discharge. The displacement of magnetically aligned BP actuators applied with a positive voltage was 450% higher than that for an applied negative voltage, which verifies the asymmetrical deformation characteristics of nanotube actuation. Charge-injected actuation of aligned BP can produce a 0.22% strain by applying a high voltage (1100 V). The aligned BP actuators exhibited a higher strain than did randomly dispersed BP actuators. The aligned BP actuators showed stable and fast responses under ambient, open air conditions without electrolytes, which offers direct experimental verification that BP actuation comes directly from carbon–carbon bond deformation due to charge and discharge processes. The nanotube BP actuators demonstrated a much faster response compared to other polymer-based actuators.