Nematic elastomers with aligned carbon nanotubes: new electromechanical actuators

TL;DR

This paper reports a novel electromechanical response in nematic liquid crystalline elastomers filled with a tiny amount of aligned carbon nanotubes, showing promise for electrically driven actuator applications.

Contribution

First demonstration of large electromechanical response in nematic elastomers with low-concentration aligned carbon nanotubes, highlighting their potential as actuators.

Findings

Effective dielectric anisotropy significantly increased by nanotubes

Uniaxial stress of ~1kPa generated by ~1MV/m field

Reproducible actuation observed over multiple cycles

Abstract

We demonstrate, for the first time, the large electromechanical response in nematic liquid crystalline elastomers filled with a very low (~0.01%) concentration of carbon nanotubes, aligned along the nematic director at preparation. The nanotubes create a very large effective dielectric anisotropy of the composite. Their local field-induced torque is transmitted to the rubber-elastic network and is registered as the exerted uniaxial stress of order ~1kPa in response to a constant field of order ~1MV/m. We investigate the dependence of the effect on field strength, nanotube concentration and reproducibility under multiple field-on and -off cycles. The results indicate the potential of the nanotube-nematic elastomer composites as electrically driven actuators.