Faculty of Engineering Tel-Aviv University, Ramat-Aviv,
Research associate, Faculty of Engineering, Tel-Aviv University, Ramat-Aviv,
Technion—Israel Institute of Technology, Technion City, Haifa,
Director, Electrical Discharge and Plasma Laboratory and Professor of Electrical and Electronics Engineering, Tel-Aviv University, Ramat-Aviv,
(Received 15 July 1996; accepted 3 December 1996)
A novel technique for the development of latent fingerprints is presented. It is based on placing a fingerprint-bearing object inside a corona discharge induced plasma. The development of various real and artificial fingerprints on metallic substrates under a wide range of conditions is studied. Using the results of the development experiments and the results of X-ray photoelectron spectroscopy, it is shown that the development is based on oxidation of the fingerprint background. This is achieved by strong oxidizers generated by the discharge process, while saturated fatty-acids found in sebaceous fingerprints protect the area beneath them, resulting in a visible fingerprint. The process is optimized by minimizing the electrode gap distance and maximizing the peak discharge voltage and the pulse repetition frequency.
Paper ID: JFS14217J