University of California engineers develop ultrasonic 3D fingerprint sensor
Engineers at the University of California, Davis have developed a new ultrasonic 3D fingerprint scanning chip that uses the same technology used in medical ultrasounds, according to a report by Factor.
The advanced fingerprint technology would be a significant security improvement for biometric authentication in smartphones.
In September, it was revealed that the same TouchID fingerprint spoofing tactic that allowed fraudsters to gain access to Apple’s iPhone 5s can also be used with the iPhone 6.
“Ultrasound images are collected in the same way that medical ultrasound is conducted,” said David A Horsley, professor of mechanical and aerospace engineering at the University of California, Davis. “Transducers on the chip’s surface emit a pulse of ultrasound, and these same transducers receive echoes returning from the ridges and valleys of your fingerprint’s surface.”
The ultrasonic fingerprint sensors are able to measure a “three-dimensional, volumetric image of the finger surface and the tissues beneath the surface,” said Horsley.
Additionally, the chip is manufactured in similar way to existing smartphone components, which would make for a relatively seamless adoption process by major brands.
The chip’s imager is made using microelectromechanical systems (MEMS) tech – already used in smartphones’ microphones, accelerometers and gyroscopes, and manufactured using a modified version of the process used to make those found in the iPhone.
“Our chip is fabricated from two wafers – a MEMS wafer that contains the ultrasound transducers and a CMOS [complementary metal-oxide-semiconductor] wafer that contains the signal processing circuitry,” said Horsley. “These wafers are bonded together, then the MEMS wafer is ‘thinned’ to expose the ultrasound transducers.”
The technology, whose details are published in the journal Applied Physics Letters, can be manufactured for a low cost at a high volume, making it feasible for the mass production needs of smartphones.
In addition to smartphones, the chip’s 1.8V power supply and low energy requirements make it ideal for other miniaturized applications.