Simulations of 3D-Printable biomimetic artificial muscles based on microfluidic microcapacitors for exoskeletal actuation and stealthy underwater propulsion

Abstract

Practical artificial muscles are highly desirable in a wide range of applications, including strength augmentation in military exoskeletons, medical prosthetics for amputees, locomotion boosters for geriatric and handicapped patients, walker robots, and acoustically quiet underwater propulsion systems. So, artificial muscles have been a subject of active research through a variety of approaches, e.g. electromagnetics, pneumatics, hydraulics, thermal expansion/contraction, piezoelectrics, shape memory alloys, and electrically active polymers. Herein we propose a new approach based on a combination of microfluidics, 3D printing/additive manufacturing (AM), and electrostatic actuation. Back-of-the-envelope calculations promise 33 MPa generated stress under feasible conditions. Respective integral architectures are described. Individual devices and 2 × 2 arrays are analyzed through COMSOL simulations. Simulations predict 10–20 % strain, which is ample for most applications. Parameter sweeps in the simulations offer quantitative insights into optimal values for maximizing the output force density. The simulations demonstrate that alternative wiring schemes produce muscle or counter-muscle behavior of the same arrays, offering novel capabilities. The proposed technology promises a major impact on a range of important applications, e.g. exoskeletons, prosthetics, walker vehicles, and stealthy undersea propulsion.