Think you’ve heard it all when it comes to the uses of 3D printing? Think again. Another week has passed and yet another intriguing example of the many potentially useful applications of additive manufacturing has come to light. Police in Michigan, USA have 3D printed the fingers of a murder victim to help unlock a mobile phone as part of their ongoing investigation into the crime!
Biometrics
It’s normally a cause for concern when police officers show up at your workplace. But in the case of Anil Jain, the officers weren’t there to arrest him – they needed his help with solving a crime.
Jain is a professor in the Department of Computer Science & Engineering at Michigan State University. He specializes in researching pattern recognition and biometrics, including fingerprint technology.
Fingerprint scanner
The Michigan police force felt that they could use Jain’s expert knowledge of fingerprint technology to help create a 3D printed copy of the victim’s fingers in his lab. The victim’s mobile phone is unlockable with a fingerprint scanner. Police hope that this replica set of fingers could give them access to the victim’s phone and shed more light on the details of the crime.
According to the original source, police made copies of all ten of the victim’s fingers just to be sure they could unlock the phone. They suspect that the victim used his index or thumb on the scanner, but they weren’t prepared to take any chances.
Such examples of 3D printing applications have been postulated before, but there is a difference between pondering the potential of something and actually attempting to use it in a real-life scenario. Despite the morbid nature of the situation, there is real excitement about the potential efficacy of this use of 3D printing technology.
How does it work in practice?
Police got lucky because the victim had a criminal record, which meant that his fingerprints were scanned when he was alive. Officers passed these scanned prints on to Jain and his team in his lab at Michigan State University, but there was a problem at first.
Standard 3D printing plastic isn’t conductive enough to close the electrical circuits on most mobile phone fingerprint scanners. People normally gain access to their phones by closing off these scanners, and human skin has the right conductivity to do this.
The clever team quickly found a way around the conductivity problem, though. By encasing the additively manufactured fingers in a layer of metallic particles, the replica fingers became readable by fingerprint scanners.
3D printing as a tool for law enforcement
Since this is an active investigation, further details are sketchy at best. The latest report is that Jain and his team are still working on refining the technology to produce the most accurate set of replicas that they can achieve.
There is one crystal clear truth here, though. If any of these replica fingers help solve the crime, it could mean that 3D printing becomes a key tool in the arsenal of law enforcement.