Experimental characterization of a dielectric elastomer fluid pump and optimizing performance via composite materials

Abstract

Dielectric elastomer is a class of soft actuators with exceptionally high strain capabilities and energy density. It is being studied for wide range of various applications and has been hypothesized to be a good material for biomedical blood pumps. We performed experimental characterization of a simple dielectric elastomer fluid pump to test this feasibility. We achieved substantial flow rates (10 mL/s) and actuation pressure (45 mm Hg) and found that dielectric elastomer fluid pump performance can exhibit significant resonance effects, with drastic reduction in performance at non-resonance frequencies. The elastomer, VHB™, a soft acrylic polymer, is frequently used to fabricate dielectric elastomer due to high deformation abilities and dielectric constant but has a well-known shortcoming of high viscoelasticity, which severely limited the dielectric elastomer pumps’ performance except at very low frequencies. In this study, we demonstrated that the introduction of a thin elastic and non-viscous layer to the VHB, such as latex, to form a composite dielectric elastomer could address this limitation. The composite dielectric elastomer pump has an increased resonance frequency, significantly improved performances at frequencies of 0.75–2 Hz, and higher maximum achievable actuation volume, flow rate, actuation pressures, and power output. Remaining challenges of realizing a dielectric elastomer blood pump are discussed.