All-Organic Electroactive Device

NASA Langley developed a novel all-organic actuator with SWCNT film electrode because commonly used metal electrodes such as silver and gold tend to constrain displacement (elongation or contraction) of an electroactive polymer at the interface. The actual output strain of the metal devices is smaller than what they can intrinsically provide. Many alternative electrode materials that could relieve the strain of movement, such as conducting polymers, have been proposed, but they are usually not thermally stable enough for most applications. The innovation is the new method for creating the all-organic flexible SWCNT film electrode, which has high conductivity and good thermal stability. SWCNTs are first dispersed into a solution and then filtered onto the surface of a porous anodized alumina membrane to form a SWCNT film. The SWCNT film is separated by breaking the brittle alumina membrane and delaminating the film. Adjusting the concentration and quantity of SWCNT solution used allows for a wide range of width and thickness for SWCNT films. The SWCNT film has the potential to be made thin enough to be transparent. The SWCNT film is then used to form the all-organic electroactive device system that can be used as an actuator. An electroactive polymer (LaRC-EAP) sandwiched by the SWCNT electrodes is fabricated by pressing the layers together at 600, 3000, and 6000 psi. By controlling the fabrication pressure, the level of physical properties, which can match with the electroactive polymers, can be adjusted and tailored appropriately.