Investigation of dust in electrohydrodynamic (EHD) systems

Convection remains the most popular cooling solution for portable consumer electronic devices. However, increasing heat generation in microelectronics and the demand for increasingly compact devices has resulted in heat fluxes that are pushing the limit of conventional rotary fan air cooling technology. Electrohydrodynamic (EHD) ionic wind pumps offer a possible solution. In this technique, applying a voltage to a sharp electrode ionizes air molecules, which are propelled by the electric field, transferring momentum to neutral air molecules, thus creating airflow and cooling. A previous paper discussed the successful integration of an EHD cooling system in a notebook computer. It demonstrated the benefits of EHD cooling technology including silence, high coefficient of performance and flexible form factor, and discussed key technical challenges for commercialization. In this paper, we focus on a concern shared by both fan and EHD cooling systems: the accumulation of dust particles, which can result in performance loss. The fundamental mechanisms of particle collection within an EHD system are discussed, and a numerical model for predicting dust deposition is presented and verified using experimental results.