NIT stamps its mark on fingerprint technology

DURGAPUR: NIT Durgapur, in collaboration with IISc Bangalore and IIT Gandhinagar, has developed a technology that promises a quantum leap in fingerprinting technology. The system, using nano materials, provides for exceptional clarity in prints, a long-standing demand by forensic experts, and may be the next big leap after digitisation of fingerprints — used extensively in Aadhaar — was developed.

Developed in Calcutta in the last years of the 19th century, fingerprinting technology has remained the mainstay of criminal science and detection. But problems remained, mainly due to prevailing collection methods, which resulted in unclear images. So far, the usual way was to collect fingerprints on dyes. But this method suffered from a lack of clarity, thanks to peculiarities in skin folds. Since deductive reasoning through fingerprinting is essentially a visual method, this lack of clarity was a big hindrance, felt forensic experts, and deductions — ironically, in a field that should have been an exact science — often had to rely on assumptions and inferences.


The new method, however, will make every minute detail of a fingerprint legible, claim experts, and contribute to foolproof detection.

Using this new technology, developed in the physics laboratories of the institute, the fingerprints are collected on luminescent nano materials, which are invisible under white light but become visible under the ultraviolet spectrum.

'50 per cent better clarity using new print technology'

The research findings have been published simultaneously in the January edition of Nature (India) and Nanoscale (UK) to rave reviews. A television team from Parliament visited the campus earlier this week to film the research so that it could be televised.

The team of researchers used zinc sulphide mixed with copper and manganese in the form of a powder, pressed fingers on them and then collected the prints on films. This is a luminescent nano material (semi-conductor particles that are a million times smaller than a millimetre) that glows in ultraviolet light and not visible in white light. The fingerprints collected in this way glow in the dark under UV light. “Every finger has ridges and furrows, and there is a fine undulation between every ridge and furrow that gets recorded every time an imprint is taken. The clarity that we have been able to achieve is at least 50% better than what we already have,” said Pathik Kumbhakar, faculty of physics at NIT Durgapur, who is the lead researcher of the project. The team also included Chandra S Tewari of IIT Gandhinagar and Praful Pandey of IISc.

Finger surfaces emit a secretion that leave an imprint on the surface on which a finger is placed. This is how fingerprints are taken. The secretion helps capture the raised ridges, leaving out the furrows, which are the dents in between the ridges.

The fingerprints that the researchers have captured on nano materials have such clarity that all minute patterns — islands, forks, cores, bifurcations, short ridges and ridge endings — which together make up the complete fingerprint, can easily be identified. Once taken on nano particles, the researchers captured the result under UV light, digitally, by capturing the glowing image on smartphones. “There is some kind of a permanence in the fingerprints collected on nano particles. Unlike dyes, which tend to fade away, these luminescent particles don’t wear off easily. We are trying to quantify this longevity now,” Kumbhakar added.

After the recent publication of the research papers, the institute has also shared the findings and conclusions with the Council of Scientific & Industrial Research (CSIR) and the human resources ministry. The Parliamentary TV team has recorded the findings, and it will most likely be televised in both houses to collect their opinions before further action.