Kloepfer, who founded Biofire Technologies, began developing his smart gun four years ago when he was only 15. Two years ago, his fingerprint-reading smart gun won the Colorado teen a $50,000 grant from the Smart Tech Challenges Foundation. Prior to that, he'd also won top honors for his smart-gun engineering project at the 2013 Intel International Science and Engineering Fair, where he was one of only 34 award recipients out of seven million high school students who entered from around the globe.
The 19-year-old is now a freshman at MIT, and he recently completed his latest prototype of a fingerprint reader embedded in a semi-automatic pistol; this one uses a Glock Model 22 .40 caliber handgun. Kloepfer inserted the stamp-sized fingerprint reader into the gun's hand grip; a circuit board and lithium polymer battery allow the sensor to read pre-authorized fingerprints and unlock the gun.
A prototype weapon from Biofire Technologies shows the circuit board embedded in the pistol grip.
The fingerprint sensor is ergonomically placed at the top of the handgrip. When a right index finger is inserted into the pistol's trigger guard, the hand's middle finger naturally comes to rest atop the fingerprint reader.
But it was Kloepfer's unlocking mechanism that made his smart gun unique among others. It uses a special wire -- an actuator-shaped memory alloy -- that when heated via a command from the gun's circuit board, contracts and unlocks the trigger mechanism. There are no motors, which would require a lot more of handgun's tiny real estate.
The fingerprint reader on an early prototype from Biofire Technologies.
A USB port on the bottom on the handgun can be used to charge the weapon's lithium-ion battery, which Kloepfer said should last at least a year.
An early prototype of the weapon can be seen in this YouTube video posted last year.
Along with perfecting the electronic-mechanical interface, Kloepfer's greatest challenge to date has been reducing the time it takes the for gun to unlock -- currently 1.5 seconds. "I expect to see that decrease to under half a second on a production model," he said.
The trigger actuator mechanism in one of Kai Kloepfer's early prototypes.
Unlike many of the smart guns produced in the mid- to late-2000s and that used decade-old processors and other outdated technology, today's weapons are taking advantage of the latest microprocessors and biometrics readers. For example, Kloepfer's fingerprint reader comes from Fingerprint Cards AB, a Swedish tech company whose biometrics are used in Google's new Pixel smartphones, and the circuit board sports an ARM Cortex A4 processor.
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