The rapid growth of the Internet of Things (IoT) increases the need for secure authentication on mobile devices, which often control IoT systems. Traditional methods like passwords are vulnerable, making biometric authentication more reliable. This research focuses on integrating fingerprint sensors into smartphone displays using thin-film transistor (TFT) technology to enable large-area fingerprint scanning, improving security for IoT applications such as healthcare, smart homes, and connected environments.
This research develops and evaluates novel pixel circuits for large-area optical fingerprint sensing in mobile devices. First, a new 2-transistor pixel topology (Figure 1) based on dual-gate a-IGZO TFT technology was designed and analyzed for high-resolution implementation, focusing on the influence of the back gate on biasing, amplifier gain, delay, and noise. The circuit was then fabricated and characterized. Next, a pixel-system architecture (Figure 2) combining Passive Pixel Sensor (PPS) with a binning method and Active Pixel Sensor (APS) modes was proposed to enable fast coarse scanning and detailed fingerprint imaging. A 16 × 16 pixel prototype array was fabricated in LTPS technology and measured. Finally, different pixel topologies and TFT technologies were compared to evaluate performance and propose improved fingerprint sensor architectures.
25/3/2026 14:00 - 16:00
Thermotechnisch Instituut: TI01.02 - aula van de Tweede Hoofdwet
