Capacitive sensors for wearable devices: fingerprint sensor and pressure sensor

Abstract

Wearable devices for health monitoring have been researched and developed in various strategies over the past decades. However, it is necessary to develop high-performance flexible wearable devices since most of them are still manufactured on rigid substrates or have large volume. In addition, not only performance but also security are important because these wearable devices must be offered individually. Therefore, this study was conducted to develop biometric fingerprint sensors for security and high performance flexible pressure sensors. First, a highly stable oxide thin-film transistor (TFT) with the short channel was developed, and then an active-driven self-capacitive fingerprint sensor was developed based on the oxide TFT. Next, a highly sensitive and stable capacitive pressure sensor using three-dimensional (3D) macroporous silicon elastomer were developed.