한양대학교 Nano Bio Tech Lab.

A high-surface-area material has recently attracted interest in actuator systems. We report on improved performance of the simultaneous electrochemical linear actuation of conducting polymer (CP)/carbon nanotube (CNT) hybrid fibers using porous structured deoxyribonucleic acid (DNA) hydrogels. It was deduced that individual DNA-wrapped CNTs had efficiently doped the PPy on its inner and outer surface through the association of PPy with the DNA via a supramolecular interaction. To assess the potential of the PPy/DNA/CNT hybrid fibers for use in electrochemical capacitors and actuators, we showed that the redox response of the hybrid fibers was improved by the addition of DNA to the PPy/CNT film. The values of the measured electrochemical capacitance (∼371 F/g in a lithium bis(trifluoromethylsulfonyl)imide aqueous solution, where the joint mass of PPy, DNA, and CNT was considered) were higher than those of previous CNT/PPy composite films with a controlled pore size (∼250 F/g). The fibers showed actuation stability with an expansion and contraction of ∼4.41% under a low potential (±1 V). DNA/PPy/CNT hybrid fibers will form the basis for new intelligent materials for applications such as bio-artificial muscles.