2016 MRS fall Meeting, Boston, USA
November 27 - December 2, 2016 (Mon - Fri), John B. Hynes Veterans Memorial Convention Center
<Poster Session : BM4-16.12>
High-Speed Electroactive Polymer Actuator Engineered by Microstructured Ion Channel for Artificial Muscle
Eunah Heo, Sangsik Park, Yongchan Kim, So Young Kim, Do Hwan Kim, and Hojin Lee
Abstract
Creating artificial muscle that emulates the capability of human muscle has been a big challenge in stretchable haptic research. In particular, ionic electroactive polymer (i-EAP) actuator has been regarded as a promising candidate for mimicking human muscle due to low operational voltage and mechanical flexibility. Artificial muscles by i-EAP actuators, however, suffer from keeping displacement and stability consistent in high operation frequencies, which comes from slow ion migration into active channel. In this manner, engineering of an optimal ion transport in the ionic films as well as mechanical properties of actuators is strongly required to allow fast actuation under electrical stimuli in the solid-state.
In this talk, we describe an unprecedented high-speed i-EAP actuator by engineering microstructure of ion channel at the interface of ionic elastomer and flexible conducting polymer electrode, Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). To this end, the PEDOT:PSS electrodes are formed onto both sides of ionic elastomer with an optimal content of ions using well-controlled spray-coating method. The actuator implemented by us was successfully operated with a large displacement up to 4mm (strain=0.55%) at an operating frequency of 0.1Hz under an applied voltage of 1.5V. Further, the actuator shows high-speed response under the bending strain of 0.15% and the displacement of 0.92mm even at frequency of 30Hz, which is equivalent to 100 folds improvement compared to the values reported in the literature. This result indicates that controlling an interpenetration depth of PEDOT:PSS chains into the ionic elastomer not only decreases an internal resistance between two electrodes, but also forms more effective and microstructured ion conducting channel, thereby leading to larger displacement and faster response of actuators even under low voltage bias.
We believe that high-speed i-EAP actuator demonstrated by us will be an effective way to implement human-interactive smart haptics capable of recognizing the human-environment interface and a novel engineering design for smart artificial muscle capable of physiologically actuating under electrical stimuli.
