ABSTRACT
Printed electronics is an evolving technology for fabricating electro-chemical and bioelectronics sensors and devices. The technology exploits a number of processes including gravure, screen, flexo and inkjet printing. In a typical printing operation, an electronically functional ink is deposited over a rigid or flexible substrate. Through the use of different functional inks and geometric patterning, passive (i.e., resistors, capacitors, inductors, electrodes) and active (thin film transistors) electronic circuit components can be fabricated. The printing technology deposits the desired thin film pattern directly on the substrate without requiring additional post-processing steps. The ability to print functional electronic circuits and devices that are low-cost and disposable has opened new opportunities for developing mechanically flexible sensor arrays. The chapter introduces several approaches to fabricating printed electronic circuits and sensors, and illustrates these concepts by describing a printed sensor that uses hydrogels to monitor changes in solution pH.
