Carbon nanotube -coated electro-active paper(EAPap) as hybrid high-displacement actuator

Electro-Active Paper (EAPap) has been investigated as an attractive EAP material for artificial muscles due to its many advantages such as lightweight, availability, low cost, large displacement output, low actuation voltage and low power consumption. The EAPap is based on cellulose material, and is shown to involve primarily transport of ions in response to an external electric field. Depending on the electrode material. EAPap has shown actuation displacement in the range of 2-4mm, at a few volts. Drawbacks of EAPap actuators include a low force output and a dependence on humidity. To address these limitations, a hybrid EAPap actuator is developed by incorporating an electrode fabricated using single-wall carbon nanotubes (SWNT)/Polyaniline (PANI) with different dopants. SWNT is dispersed in 1-Methy-2-pyrrolidone (NMP), and the resulting solution is used as a solvent for PANI and the various dopants. The SWNT/PANI/NMP solution is then deposited on the EAPap by spin coating. The coated EAPap is dried in a vacuum oven. Raman spectroscopy, X-Ray diffractometry and SEM tests are taken to confirm that the SWNT/PANI/dopant electrode material is successfully prepared by in situ polymerization. The actuation output of the SWNT/PANI/EAPap samples is tested in an environmental chamber in terms of free displacement and blocked force. When the SWNT/PANI/Cl^- coated hybrid actuator is excited with 7Vp-p, a maximum displacement of 3.1mm and a maximum power output of 0.29mW are obtained. The hybrid actuator shows an improved actuation force as a result of enhanced stiffness of EAPap.