Electroactive Polymers (EAPs)
Publishing Time:2016-12-28

Electroactive Polymers (EAPs)

Electroactive polymers (EAPs) are typical soft active material that can response to external electric stimuli. Dielectric elastomer (DE) is one of the representative electroactive polymers and is widely used as actuators or sensors. It is actually a sandwiched structure consists of one single elastomer film and complaint electrodes on both surface. Subject to an external electric field, DE will reduce in thickness and expand in area due to Maxwell’s stress. When the electric field is revoked, it can restore to its original shape.

Fig.1 Schematic of a dielectric elastomer membrane subjected to forces and an electric voltage.

Based on this property, dielectric elastomer can be used to create intelligent transducer, and has long been desired for the development of aerospace, astronautics, mechanical engineering, artificial muscle, biologically inspired robots and biomedicine. Our group focuses on synthesis, actuator design, constitutive theory and stability of dielectric elastomers.

(a) In order to offer guidance in the design and fabrication of excellent actuators featuring dielectric elastomers, we investigate constitutive model, large deformation, electromechanical instability, snap-through instability, thermo-electro-mechanical instability and typical failure model of dielectric elastomers and its composites.

(b) The BaTiO3 based dielectric elastomer composite is fabricated and tested. The stress–strain relationship, dielectric constant and the electro-induced deformation of carbon nanotube based dielectric elastomer composite are also demonstrated.

(c) We have fabricated the rolled, folded, inflated and stacked actuators of dielectric elastomer and their mechanical and electrical properties are also investigated. Based on the stacked dielectric elastomer actuator, the energy harvest device and Braille display are designed and fabricated, and their performance demonstration is subsequently conducted.

Fig.2 Nominal electric field and stretch of dielectric elastomer undergoing polarization saturation

Fig.3 Energy harvest device using stacked dielectric elastomer actuators