Developmentof Latent Fingerprint with Spray Deposited Metal Thin Films

We experimentally addressed the development of latent fingerprint with spray deposited gold/zinc thin films.The influence of the surface properties of materials on which latent fingerprint was left, including but not limited to napkin, print-paper, newspaper, brown paper, cardboard, opaque plastic surface, tin foil, glass, ceramic tile and silk, on the visual effect of sweat/dust/blood/sebum/grease fingerprints was investigated to optimize the coverage (or thickness) of Zn film.The results show that the properties of materials surface and features of fingerprint all have a major impact.To be specific, when it comes to optimized visual effect of sweat latent fingerprint, the Zn film thickness on the materials surface can be listed in an ascending order:napkin<print-paper<newspaper<cardboard<brown-paper.In addition, a fingerprint on impermeable material required a thicker Zn film than that on a permeable material did.