Output Force Density Saturation in COMSOL Simulations of Biomimetic Artificial Muscles

Abstract

Many modern applications, such as undersea drones, exoskeletal suits, all-terrain walker drones, prosthetics, and medical augments, would greatly benefit from artificial muscles. Such may be built through 3D-printed microfluidic devices that mimic biological muscles and actuate electrostatically. Our preliminary results from COMSOL simulations of individual devices and small arrays (2 × 2 × 1) established the basic feasibility of this approach. Herein, we report on the extension of this work to N × N × 10 arrays where Nmax = 13. For each N, parameter sweeps were performed to determine the maximal output force density, which, when plotted vs. N, exhibited saturation behavior for N ≥ 10. This indicates that COMSOL simulations of a 10 × 10 × 10 array of this type are sufficient to predict the behavior of far larger arrays. Also, the saturation force density was ~9 kPa for the 100 μm scale. Both results are very important for the development of 3D-printable artificial muscles and their applications, as they indicate that computationally accessible simulation sizes would provide sufficiently accurate quantitative predictions of the force density output and overall performance of macro-scale arrays of artificial muscle fibers. Hence, simulations of new geometries can be done rapidly and with quantitative results that are directly extendable to full-scale prototypes, thereby accelerating the pace of research and development in the field of actuators.