Theoretical analysis based on particle electro-mechanics for Au Pearl Chain Formation

This paper analyzes the fundamental mechanisms in driving Au pearl chain formation (PCF) based on dielectrophoresis (DEP) force. From experimental results, the PCF process strongly depends on the voltage and the frequency applied on electrodes, but weakly on the sizes of particles, which appears to be contrary to theoretical expectations. To explain the above phenomenon, we estimated the DEP force and the Brownian motion imposed on the Au nanoparticles, and then investigated the AC electro-osmosis force and the electro-thermal force which may possibly affect the PCF rate. Numerical modeling to compare the forces is presented. By matching experimental and numerical results, we validate the scaling laws of the DEP force and electro-mechanics in the PCF of Au nano-particles.