Spring type conducting polymer actuator working in air

Although major advances in actuator performances have been obtained in the last few years, the actuation of conducting polymer (CP) actuator is still limited to bending movement in liquid electrolyte. It restricts the various application fields of CP actuator. So in this study, spring type CP actuator which can produce linear movement and work in air is prepared. It is composed of two polypyrrole (PPy) films having different actuation mechanism and polyurethane (PU) based solid polymer electrolyte (SPE). Even though the ionic conductivity of PU based SPE is low, the actuation behavior of CP actuator especially working in air is much influenced by the flexibility rather than the ionic conductivity of SPE. Then PU based SPE with high flexibility is used in a spring type CP actuator. The morphology of PPy films, ion conductivity of SPE, actuation movements according to its length and applied voltage and loading ability of actuator were investigated. SPE had a maximum conductivity of 2.20 × 10−6 S/cm at room temperature for 15 wt% of Mg(ClO4)2 salts and the actuator which was fabricated in 21 mm length showed maximum displacement at 12 V. Also it was confirmed that spring type CP actuator could Exhibit 10 MPa of loading ability through the tensile strength test. As a result, solid-state spring type CP actuator having both linear movement and loading ability was demonstrated.