Particle-Induced Electrostatic Repulsion within an Electric Curtain Operating below the Paschen Limit

The electric curtain is a platform developed to lift and transport charged particles in air. Its premise is the manipulation of charged particles; however, fewer investigations isolate dielectric forces that are observed at lower voltages (i.e., less than the Paschen limit). This work focuses on observations of simultaneous dielectrophoretic and electrostatic forces. The electric curtain was a printed circuit board with interdigitated electrodes (0.020 inch width and spacing) coated with a layer of polypropylene, where a standing wave or travelling wave AC signal was applied (50 Hz) to produce an electric field below the Paschen limit. Soda lime glass beads (180-212 mu m) demonstrated oscillatory rolling via dielectrophoretic forces. In addition, several particles simultaneously experienced rapid projectile repulsion, a behavior consistent with electrostatic phenomena. This second result is discussed as a particle-induced local increase in the electric field, with simulations demonstrating that a particle in close proximity to the curtain's surface produces a local field enhancement of over 2.5 times. The significance of this is that individual particles themselves can trigger electrostatic repulsion in an otherwise dielectric system. These results could be used for advanced applications where particles themselves provided triggered responses, perhaps for selective sorting of micrometer particles in air.

Automated summary

The electric curtain is a platform for lifting and transporting charged particles in air. This study focuses on observations of simultaneous dielectrophoretic and electrostatic forces, which are less investigated at lower voltages. The electric curtain, consisting of interdigitated electrodes coated with polypropylene, generates an electric field below the Paschen limit. Results show that soda lime glass beads experience oscillatory rolling via dielectrophoretic forces and rapid projectile repulsion consistent with electrostatic phenomena. Additionally, simulations demonstrate that particles in close proximity to the curtain's surface produce a local field enhancement. These findings have implications for advanced applications involving triggered responses of particles.