A large area flexible array sensors using screen printing technology

A flexible electronics sensor for large area sensing was developed using a screen printing technology with the thixotropy sol-gel materials to form the microstructure patterns on two polyimide (PI) sheets. A flexible sensor is 150× 150 mm², including posts, resistances, bumps, and electrode traces. The space between the top electrode and the resistance layer provided a buffer distance for large bending. Experimental results show that array microstructures have good morphological profiles at a screen speed of 10 mm/s, a squeegee pressure of 213 kPa, and a separation speed of 0.4 mm/s using the print-print mode. A membrane with a bump protrusion had a large displacement and a quick sensitive response because the bump provided a concentrated force of von Mises stress on the membrane center. For printing thick structures, diffusion effects and dimensional shrinkages can be reduced when a paste material with a higher viscosity is used. The results exhibit a potential for using in the flexible sensing and higher temperatures. In additional, the fabrication is the low cost and potential higher throughput in flexible electronics applications.