The deposition of fingerprint films

Abstract

The contact of human fingers with solid surfaces and their subsequent separation have been studied microscopically. Scanning electron microscopy and contact angle measurements have been applied to examine the deposit film. When a finger touches a surface, a film of liquid present on the finger spreads to produce apparent contact over much of the fingerprint ridge area. Lifting of the finger causes the film to recede and leave a deposit which may be either a distribution of droplets on a thin contaminating layer of adsorbed molecules, or a continuous film: which type is dependent on both the composition of the fingerprint and the nature of the substrate.

Physical developer method for detection of latent fingerprints: A review

“…3 The other half consists of organic derivatives like, urea, creatinine, choline, lactic acid, sugars, uric acid, amino acids and proteins. 4 The physical developer technique for detection of latent fingerprints is based on the interaction between lipids and fatty acid constituents of sweat residue, with colloidal silver particles. 5 It had earlier been known that colloidal silver particulates have affinity for such organic derivatives.…”

The Synthesis and Morphology of a Perfluoroalkyl Oligosiloxane@SiO2 Resin and Its Performance in Anti-Fingerprint Coating

“…Therefore, a study on how to keep touchscreens free of fingerprints and make them easier to clean should probably focus on developing transparent hydrophobic and oleophobic coatings; this has become an urgent and primary problem that needs to be solved [4], especially as electronic devices and wearable electronics have developed rapidly. Thus, the demand for anti-fingerprint materials is expected to increase greatly in the next few years [5].…”

Multimetal deposition method for detection of latent fingerprints: a review

“…Besides water content, eccrine sweat contains up to 1% of the other substances of which inorganic salts constitute about one-half (Kuno, 1956). The other half is constituted by organic products like urea, creatinine, choline, lactic acid, sugars, uric acid, amino acids and proteins (Scruton et al, 1975). The multimetal deposition technique for detection of latent fingerprints is based on the interaction between these organic biomolecules, especially the amino acids and proteins with colloidal gold particles.…”