Screen-Printed Transparent Flexible Sensors for Liquid Solvent Detection

Transparent flexible resistive sensors have generated significant interest within the rapidly evolving field of stretchable electronics, particularly for applications that require transparency, fatigue resistance, and high sensitivity. Our research proposed a screen-printing strategy to produce transparent flexible resistive sensors characterized by their sensitive responses to droplet variations and endowed with the capability for repeated utilization utilizing silver nanowires (AgNWs) ink and polyethylene terephthalate (PET) substrate. Plasma treatment was implemented to enhance the electrical conductivity of the printed circuit, which can fuse the AgNWs into highly connected frameworks without deteriorating the transmittance properties of the circuit board. Additionally, the cyclic stability in the solution was improved by applying a carbon coating on the AgNWs-based sensors facilitated by the shadow mask. The resistive sensors demonstrate varied current responses when exposed to liquids with differing conductivity levels while maintaining excellent optical performance with an average transmittance of 77.6% at a visible wavelength of 550 nm. The transparent flexible sensors exhibit prospective applications in biomedical sensing, industrial process control, and intelligent packaging for food safety, thereby providing a thought for the next generation of artificial sensors.