Electrical microparticle acceleration by high-speed membrane deformation

Abstract

In this study, we conducted experiments to explore the potential of a low-power exploding foil initiator for accelerating microparticles through high-speed membrane deformation. This involved the use of a conductive layer with a conversion section known as a “bridge,” which was positioned between the substrate and the cover layer. The application of pulsed electrical energy led to Joule heating at the bridge, while the vaporized gas generated impulsive loading, resulting in the deformation of the cover layer. According to the principles of energy conservation, 8.7% of the electrical input energy was converted into kinetic energy for the membrane. This deformation process achieved a velocity of 800 m/s, with a corresponding strain rate of 1.6 × 107 s−1. The applied impulse predominantly induced extension stresses in the cover layer rather than bending stresses. Under these conditions, a 17.5-µm radius polylactic acid bead was propelled and subsequently captured by a silicone gel layer, resembling human dermic skin. Considering factors such as particle clustering and deceleration due to air resistance during supersonic flight, assuming a normal incident angle, it was estimated that approximately half of the ejected particles could reach the human dermic layer, located 200 µm beneath the skin surface. These findings suggest that pulse discharge is a promising method for inducing high-speed membrane deformation, and the electrical microparticle accelerator holds potential for applications in needle-free drug delivery.