Highly Sensitive Flexible Pressure Sensor by the Integration of Microstructured PDMS Film With a-IGZO TFTs

The development of flexible and highly sensitive pressure sensors is critical for the realization of wearable health monitors and electronic skins. However, the sensitivity, flexibility, and large-area fabrication of pressure sensors remain the key challenges for their practical applications. In this letter, we present a novel pressure sensing system in an amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor (TFT) configuration comprised of a microstructured polydimethylsiloxane (PDMS) capacitor fabricated on a 200 mm × mm flexible substrate. The microstructured PDMS thin film shows the average sensitivity of 0.1 kPa
^-1
and response time of <;190 ms for the pressure of 12 kPa. Through the amplification effect of the a-IGZO TFT, the device shows a high sensitivity in the subthreshold region for ultra-low-pressure regime (≤1.5 kPa) detection and good linearity in the linear region for low-pressure regime (≤7 kPa) detection. These results demonstrate a novel approach to pressure-sensing intelligent products.