Review—Inkjet Printing of Metal Structures for Electrochemical Sensor Applications

Inkjet printing has emerged as a leading technology for additive manufacturing of electronic devices. It is particularly attractive in applications that require low waste, low-cost fabrication techniques. Most printing processes for electronic device applications involve the fabrication of metal structures owing to the availability of metal-based inks and the high quality structures that can be produced using these inks. As a result of rapid advances in the development of sensor-dependent technology areas like IoT and flexible/wearable electronics, inkjet printing has recently expanded into the sensor area due, in part to its inherent compatibility with a wide variety of polymer substrates and roll-to-roll processing. This review focuses on the development of inkjet-printed elemental metal structures for electrochemical applications. Included in this paper is a review of commonly used and newly emerging ink technologies, post printing sintering processes, functionalization of printed metal surfaces to enhance sensing capabilities and a variety of inkjet-printed electrochemical sensors including gas sensors, ion sensors, pH sensors, glucose sensors, and biomolecule sensors.