Researchers from NTU's School of Mechanical and Aerospace Engineering (MAE) have successfully developed Singapore's first fingerprint detection and imaging device that is capable of identifying and capturing "hard to detect" fingerprint images. This device overcomes some limitations of the existing fingerprint techniques.
Fingerprints are unique and thus useful in solving crimes. However, not all fingerprints left behind can be identified or captured using conventional methods. These include fingerprints that are too old, faint or which overlap. Present methods also cannot detect fingerprints left on backgrounds with interfering patterns and those left on certain textured paper, such as paper on which common dollar notes are printed.
The research team led by Assoc Prof Seah Leong Keey is using a patented optical and signal processing technique to develop a device that is sensitive enough to provide the contrast needed to identify the most obscure and faint fingerprints, and provide clear images of these obscure fingerprints. This phase resolved (PR) optical imaging technique is based on the phase shift occurring on the fluorescence emissions from the background and fingerprints, when excited by modulated laser, depending upon their fluorescence lifetime values. The technique enables imaging of older fingerprints of more than one year, on different substrates with strong background fluorescence.
NTU and Singapore Police Force are working together on this project. Trials of this innovative fingerprints detection and technology system had been conducted by SPF and it has found that the results obtained were excellent and will certainly enhance police capability to recover latent fingerprints at crime scenes.