Design and Integration of Organic Printed Thin-Film Transistor-Based Soft Biosensors for Wearable Applications

Soft sensors that emulate the modulus of human skin have shown significant potential for wearable sensing applications by ensuring robust, conformal contact that enables the acquisition of high-quality signals. Organic thin-film transistor (TFT)-based pixelated soft sensor arrays have been crucial for advanced spatiotemporal signal measurements, thanks to their active-matrix configuration, which minimizes signal crosstalk. Despite these advancements, challenges such as limited sensitivity, high power consumption, and the need for cost-effective, large-area integration technologies persist, hindering their practical application. This paper explores strategies for developing high-performance TFT-based soft sensing arrays. We begin by discussing the design principles for organic TFT-based sensors, offering strategies to enhance sensitivity while reducing power consumption, with a focus on the underlying device physics. We also introduce a method for ultrathin, large-area, high-performance TFT integration using systematic inkjet printing technology. To demonstrate the practical applications of our approach, we present high-performance spatiotemporal measurements of arterial pulse waves using active-matrix pressure and optical sensing arrays. The low-power, high-sensitivity, and large-area integration strategies discussed in this paper are expected to significantly advance organic TFT-based sensors, paving the way for their practical application in healthcare, wearable technology, and environmental monitoring.