Numerical Studies on Nano-particle Removal with Micro-droplet Spray

Nanoparticles are difficult to remove because it is much more difficult to deliver the necessary force to smaller dimensions. We investigate in this paper a new method using micro-droplet spray to remove nanoparticles from solid flat surface. With a droplet diameter between 50 and 100 mum, we evaluate the lift force and drag force acting on spherical particles. The particle diameter is less than 100 nm. The hydrodynamic force is a function of initial impact velocity and particle radius. Under different condition, we simulate droplet impact progress and calculate the hydrodynamic force. Comparing with adhesive van der Waals force, proper condition is found to remove nanoparticles from surface