Ultra-Thin and Flexible Biometric Imager Quickly Captures High-Resolution Fingerprints, Vein Images
Using low-temperature polycrystalline silicon in thin-film transistors (LTPS TFT) technology, the flexible sensor captures at 508 PPI.
Researchers from the University of Tokyo and Japan Display Inc. have unveiled a new type of flexible biometric sensor they claim is ideal for both authentication and vital sign measurement — and measuring just 15 micrometers in thickness.
"Our laboratory focuses on the development of flexible electronics, especially organic electronics," explains Tomoyuki Yokota of his team's work in an interview with TechXplore. "In our previous work, we developed an ultra-flexible OLED and organic imaging sensor for bio-medical applications, yet its resolution and speed was not enough to take a fingerprint image. The conformable imager we presented in our paper solves this problem by integrating LTPS TFT [low-temperature polycrystalline silicon in thin-film transistors] and an organic photodetector."
The resulting imager, measuring just 15 micrometers thick and flexible enough to curve around a wrist, offers a resolution of 508 pixels per inch (PPI) at a 41 frames per second (FPS) capture rate — and can be used for both fingerprint and vein capture as a biometric authentication device and to monitor health conditions by analyzing the wearer's pulse wave, even simultaneously.
Initially, Yokota's team is investigating the integration of the imaging technology into consumer wearables, in particular smart watches; it is also currently exploring potential applications for the technology in the medical sector. Neither announcement, however, includes a roadmap for commercial availability.
The team's work has been published in the journal Nature Electronics under closed-access terms.
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