Bio-inspired bipennate artificial muscles based on rolled dielectric elastomer actuators

This proposes to imitate the architectural arrangement of human bipennate skeletal muscles and presents various configurations of bio-inspired bipennate artificial muscles in which rolled dielectric elastomer actuators serve as fascicles. The rolled actuators are realized by rolling two mats of polydimethylsiloxane, interleaved with two electrodes made of carbon black nanoparticles in polydimethylsiloxane. The first configuration of bipennate artificial muscles is made of two fascicles. An analytic kinematic model is derived to describe the mechanical properties of this configuration. An electromechanical characterization is performed to measure the axial forces and axial displacements of the bipennate artificial muscle when electric fields are applied, and to analyze the effects of different pennation angles. The experimental results show that with higher pennation angles, the artificial muscle exhibits higher displacement and lower force compared to the parallel configuration, when pennation angle is 0 . Bi-pennate artificial muscle prototypes with more fascicles are fabricated to mimic the more complex configuration of the rectus femoris muscle. The experimental results show that the axial force increases with the number of fascicles, while the axial displacement is dominated by the smallest pennation angle.