Time-dependent deformation of artificial muscles based on Nylon 6

Abstract

Considering the potential applications of the Nylon 6 with thermal-induced deformation, we studied the creep deformation of non-twisted Nylon 6 wires and Nylon 6 artificial muscles as functions of annealing temperature. For comparison, we also studied the creep deformation of chicken muscle fibers in a temperature range of 20 to 35 °C. The experimental results showed that we could use the standard linear viscoelastic model to describe the creep deformation of the chicken muscle fibers, the non-twisted Nylon 6 wires, and the Nylon 6 artificial muscles. A simple method was developed to calculate the mechanical (elastic) constants and viscous resistance coefficient (viscosity) of the three different materials. The activation energy for the creep deformation of the chicken muscle fibers in the temperature of 20 to 35 °C was 18.79 kJ/mol. For the non-twisted Nylon 6 wires, the activation energy for the creep deformation was generally larger than that of the chicken muscle fibers, and was dependent on the annealing temperature. For the Nylon 6 artificial muscles, the activation energy for the creep deformation was smaller than that of the chicken muscle fibers.