Development of an Artificial Muscle based on an Electroosmosis-Driven Magnetic Responsive Hydrogel

Abstract

Pneumatically driven artificial muscles are lightweight and have high power density, but they require large compressors in addition to other auxiliary components, which limits their portability and overall utility. This has led to an increased amount of interest in investigating alternative sources to generate pneumatic pressure. Hydrogels are a promising option as they are lightweight, possess good mechanical properties, are easily fabricated, and can generate various mechanical responses (e.g., swelling) from different external stimuli (e.g., pH, temperature, light, electricity, magnetic fields, etc.). However, these actuators often suffer from low force generation and slow response times. In this work, a proof-of-concept novel artificial muscle was fabricated. The artificial muscle was based on a hydrogel placed in an electrolyte solution, which was then surrounded by a semipermeable membrane. The hydrogel swelled in the presence of a magnetic field, with the effect further amplified by electroosmosis. The combination of electroosmosis and embedding magnetic particles within the gel was chosen to improve the response me, while harnessing the electroosmotic turgor pressure enhanced force generation. Future work will look to further characterize the performance of the artificial muscle and understand the feasibility of the muscle for wearable applications.