Scaling Laws for Electrohydrodynamic Air Movers

As modern electronic devices become more compact and capable, device cooling has become critical not only for the reliability and stability of the electronic circuitry, but also for the comfort of the user. Forced convection can be effective at removing heat to the ambient environment. However, considerable implementation challenges remain for cooling solution thicknesses below 6mm, where the height of rotary fans is a limiting factor. While scaling laws for fans have been previously reported in the literature, the scaling rules for electrohydrodynamic (EHD) air movers have not been widely studied. This paper explores the impact of thickness, width, and input power on pressure and airflow of EHD air movers using coupled-physics modeling, with experimental validation of the results. Device thicknesses were in the 2 to 6mm range, device widths in the 10 to 100mm range, and input powers between 0.25W and 2.5W.