Published on October 30, 2007
When a fingerprint is damaged by water, small residues of fatty acid remain. Chemicals created through nanotechnology can often detect these residues.
Even though the fingerprints may have dissolved or faded, with nanotechnology, forensic officials can still get a print to make further criminal traces.
To enhance the fingerprint verification process, a research team at the Asian Institute of Technology (AIT) has developed a method to use nanotechnology to get a fingerprint, even if the print has faded.
The project is part of nanotechnology development projects supported by the Nanotechnology Centre (Nanotec) under the National Science and Technology Development Agency. AIT is also one of Nanotec's eight centres of excellence for nanotechnology development.
Nanotec's director Wiwut Tanthapanichakoon said the project was to adopt nanotechnology to develop a new method to enhance the forensic fingerprint process. It uses nano-sized bioadhesive chitosan combined with gold nanoparticles to develop a new substance that could capture a fingerprint.
Fingerprints are key evidence in tracing criminals, but many times forensic officials find it very difficult to get a print that has faded due to water or other problems.
To overcome this, the development focuses on the lipid residue or fatty acid which is normally left in fingerprint marks, even if it has been submerged or hit by rain. Using the new substance developed with nanotechnology will assist officials to see and get the remaining print from the scene.
In a fingerprint, around 99 per cent is sweat while 0.8 per cent is salt. Only 0.2 per cent is fatty acid. Wiwut said both sweat and salt were easily destroyed by the environment, but not the fatty acid.
The research team therefore tried to find suitable substances that could interact with the fatty acid to make the lipid residue appear in the form of a fingerprint.
"Since the lipid residue is left in very small quantities it's necessary to use nanotechnology to make the size of the substances very small so they can scatter in the small gaps of print residue," he said.
Experiments found that the new substance could make faded fingerprint marks appear.
AIT and Nanotec are working on registration of a patent for the new method.
The new substance can now be produced at laboratory scale.
However, Wiwut said the centre planned to work with the private sector to license the technology for mass production.
The development, Wiwut added, could also be improved to check for addictive substances in the fingerprint mark. "If we make a more in-depth analysis of the lipid residue we can find addictive substances which come with the fatty acid.
"We plan to find suitable substances to combine with chitosan and gold nanoparticles to detect addictive drugs from fingerprint marks," he said.
Wiwut believed the next development would assist police to not only get fingerprints of suspects in criminal cases but also tell the addictive status of the fingerprint's owner, which could be important information when tracing criminals.