Formation of gold Nano-particle chains by DEP — a parametric experimental analysis

Experimental results on varying particle size and dielectrophoretic (DEP) parameters, including voltage and frequency, are reported in this paper for investigating their effect on Au nano-particles Pearl Chain Formation (PCF). PCF was observed from 10kHz to 5MHz for 100nm gold Nano-particles (NPs), and 100kHz to 10MHz for 10nm gold NPs. Variations in formation rate were detected when the applied voltage and particle size varied. With higher voltage, pearl chain begins to form at higher rate and the formation time decreases. The optimum frequency of the gold NPs PCF shifts to higher frequency region when the particle size decreases. Theoretical analysis was carried out by applying the theories of DEP force and AC electrokinetics to explain the observations in the DEP frequency ranging from 10 Hz to 10MHz.