Flexible fingerprint sensor is expected to realize embedded security access control

According to the James Consulting, researchers from the Belgian Microelectronics Research Center (IMEC) and the Dutch Applied Science Organization (TNO), the Holst Center researchers showed a test for detecting fingers. New flexible, large area sensor technology for palm prints. With a thickness of less than 0.2 mm and no large prisms or moving parts, the new sensor can be embedded in objects such as mobile phones and door handles to create an "invisible" but secure access control system that recognizes that the scanned object is alive rather than a phantom. Or a fake person.

The technology paves the way for low-cost sensors for large-area finger and palmprint scanners, which will be on display at the Information Display Association (SID) 2018 Display Week Innovation Zone in Los Angeles, USA, and will be in Belgium. The IMEC Technology Forum (ITF) in Antwerp is on display. The two demonstration machines will demonstrate the technological potential for high resolution and large area effective detection areas. Among them, the 6 x 8 cm, 200-ppi demonstration machine is large enough for the 4-finger scanners currently used by border management and provides adequate image quality for basic identification applications. At the same time, the slightly smaller 500 ppi demonstration machine provides higher image quality, meets FBI standards, and is sufficient for law enforcement agencies to visualize details and pores for more powerful identification.

Like the Holst Center's early flexible X-ray detectors, this fingerprint sensor combines an organic photodiode front panel, an oxide thin film transistor (TFT) backplane (originally developed for flexible displays) and a thin film barrier for protection. Together. All three technical elements have been or are being transferred to industrial production to expand and commercialize. The sensor reads hand fingerprints or palm prints by detecting visible light (400 to 700 nanometers) reflected from the skin surface. Moreover, they can also detect part of the light that penetrates the skin before reflection. This allows them to perceive the heartbeat from changes in the capillaries of the hand, thereby verifying that the scan mark is from a living person.

In addition, by using different photodiode materials, the sensor's functionality can be extended to other wavelengths, such as near-infrared (NIR). This technology will enable new authentication modes, such as identification by hand vein pattern, which is even more specific to individuals than fingerprints. Near-infrared sensors can also be used for other purposes such as blood oxygen monitoring, night vision and 3D facial recognition.

Holz Center project manager Hylke Akkerman said: "The flexible fingerprint sensor demonstration machine demonstrates the versatility and maturity of the flexible electronics technology being developed by Holst Center. Since the underlying technology has been applied to the flat panel industry, it is the new flexibility. The manufacture of fingerprint sensors has established a fast track, and we are looking for industry partners to take this step."