Techniques to investigate the application of cold spray in fabrication of nanoplasmonic films : parameter identification

Abstract

Abstract: The decomposition of a complex system allows identification of its interacting variables. In this article the coupling between the Cold Spray (CS) thin film fabrication and functional properties in Surface Plasmon Polaritons (SPP) are investigated with a view to optimise the CS fabrication process in nano thin films. There are many reported advantages of the cold gas spray over other thermal spray technologies. However the fabrication of thin films by cold gas is limited on the capability of the transport system. This study is meant on finding ways to improve the cold gas spray for deposition of nano particles. In particular, the deposition of plasmonics nano particles for functional films in the nano scale regime. Since the requirements for each film application are different, this study is specifically targeted at films used in biosensor technology with a focus on the plasmonics sensor that use gold or silver nano particles. The paper gives the details of the parameter identification process that was used to determine missing links between the cold spray process and the optical functional thin film characteristics. In the preliminary study, intuitively, the systems engineering and pattern recognition techniques were used to explore the most probable driving variables for the cold gas coating process in functional films. This process determines the deposition parameters that characterize the surface roughness, interface roughness and film thickness as would be required for functional thin films. We have since designed a systematic numerical process for the iterations towards this direction. This study opens new avenues for further research and advancement of the cold gas spray method in nano thin film