The list of applications for 3D printing has grown by leaps and bounds over the past few years as more users and companies have adopted the technology.
The latest addition to that list comes from an unusual request by the police as part of an investigation into a murder.
According to a Fusion report, authorities approached Michigan State University professor Anil Jain last month with the request to create 3D-printed replica of a dead man's fingers.
Jain, a computer science professor involved in biometrics technology such as fingerprint scanners, was not able to share specific details on the murder case as it is still ongoing. However, the gist is that the police would like to access the smartphone of a murder victim, as they believe there are clues on the identity of the killer in the device. The authorities, instead of going to the manufacturer of the fingerprint scanner-equipped smartphone, decided to try having Jain recreate the fingers of the murder victim.
The police had copies of the murder victim's fingerprints that were taken while he was alive, as he was previously arrested. The fingerprint scans were forwarded to Jain and Sunpreet Arora, his PhD student, who used the scans to create the 3D-printed replica of all ten digits of the murder victim.
While the thumb and index fingers are the most commonly used ones to create the fingerprint lock on devices, all ten digits were created just to be sure they have the one that will unlock the smartphone.
However, a simple 3D-printed finger would not be enough to unlock a smartphone, due to the capacitive nature of the fingerprint scanners. The skin of a user's fingers is conductive enough to close the electrical circuits of fingerprint scanners to make them work, but the plastic of a 3D-printed finger will not be able to do the same thing. To solve this, Arora coated the replica fingers with metallic particles to make it possible for fingerprint scanners to read the fingerprints.
The replica fingers are still undergoing testing, with Arora claiming that they will be sent to the authorities after a few weeks of sufficient testing has been done. The police will then use them to try to unlock the murder victim's smartphone.
The solution to unlock the murder victim's smartphone to progress the investigation is certainly an innovative one. However, Electronic Privacy Information Center executive director Marc Rotenberg said that the method raises the troubling concern that other people may unlock other people's smartphones without their consent, using a similar technique.