By Kevin Fitchard

As Orwellian as it might seem, there may soon be a day when our cell phones are tracking our fingerprints. But if Atrua Technologies has its way, cell phone users surely won't mind.

Atrua is one of the handful of companies trying to unlock the power of the fingerprint to create a new way to interface and operate a phone. Called haptic processing, the technology uses the unique ridges, peaks and valleys on every human fingerprint to create the equivalent of a biological joystick that is essentially as sensitive and precise as human touch.

Originally a company focused on fingerprint identification for security purposes, Atrua has now broadened its scope to create a touch navigation system that, it believes, will revolutionize mobile data on the handset. While at first the touch-sensitive pad it proposes installing on a handset looks like a miniature version of the touch pads common on so many laptops, the versatility of its sensor is many times more complex, said Anthony Gioeli, president and CEO of Atrua.

“All a touch pad sees is a blob moving around its surface,” said Gioeli. “Our technology is orders of magnitude more precise. Instead of tracking the movement of an object, it is tracking the movement of the ridges on your finger across the sensor. Even the slightest twist of your finger is detected.”

Essentially, the silicon sensor beneath the surface of the phone tracks minute electrical charges emitted by the human body. The sensor, however, is so sensitive that it detects stronger electrical signals emitted by the ridges in a fingerprint, because they are closer to the sensors service, and registers weaker signals from that print's valleys, even though they are only micrometers further distant. The sensor uses that data to compose what is basically an electronic photograph of the fingerprint. Whenever that finger is moved across the sensor's surface, it continuously retakes that photograph, following the individual ridges' movements against each previous picture. That movement is then mimicked down to the tiniest detail in the interface of the phone.

Unlike a regular touch pad, the sensor can detect a finger's rotation in several directions and along several axes. The technology can even register slight pressure shifts as pressing a fingerprint into the phone mashes the peaks and valleys closer together.

This haptic technology can be applied to almost any application. A game that was once controlled by a five-way thumb switch and several buttons could now be controlled with a single digit resting on a pad, said Marc Ostrowski, Atrua's director of marketing. “You could create a driving game, in which you steered the car simply by rotating your finger,” Ostrowski said.

Phone commands also could be mapped to unique movements of the finger, and even the unique prints of individual fingers could be used to trigger different options on a data-enabled device. An index finger would launch Amazon.com while a ring finger would call up an e-mail account.

Atrua envisions haptic technology replacing all of the confusing buttons on every mobile phone except for the number pad itself.