Inkjet Printing of Functional Polymer Composites for Chemiresistive Gas Sensors

Drop-on-Demand Inkjet printing can be used as an effective technique to deposit the sensing layer in chemiresistive gas sensors. In this type of gas sensors, a composite containing an insulating polymer mixed with a conductive filler is used for sensing analytes. However, formulation of inks containing functional materials remains challenging due to rheological constraints imposed by the inkjet printer. Here, we show the process of ink formulation for functional inks containing polyvinylpyrrolidone (PVP), a polar polymer, and carbon black (CB). We formulated composite inks containing PVP with different molecular weights (40 and 360 kDa) and studied their inkjet-abilities based on their shear viscosity and particle size distribution. Composite inks were successfully printed onto the sensor platforms and their electrical properties were characterized.