High resolution, large height interdigital electrodes fabricated by non-contact electric-field-driven micro-3D printing

Interdigital electrodes (IDEs) have been widely utilized in environmental monitoring, biomedicine, food safety, etc. However, existing technologies still face challenges in fabricating highly sensitive IDEs with high resolution and large height. This work presents a new method for preparing IDEs using non-contact electric-field-driven (NEFD) 3D printing. The copper foil is mounted on an insulated nozzle as an extraction electrode to generate an electric field with the substrate through electrostatic induction. The consistent printing of line width and line spacing of IDEs and the law of large height printing are investigated. IDEs with line width, line spacing of 10 μm, and height of 20 μm were obtained by optimizing the printing process. The sensitivity of the IDEs could reach up to 53120 Ω/ppm with a detection limit of 0.01 ppm using sulfate solutions with different concentrations (0.01–100 ppm). This method provides a new approach for preparing high resolution, large height IDEs. •New method for fabricating high resolution and large height interdigital electrodes.•The sensor can detect ultra-low concentration solution with high sensitivity.•The method is low-cost and environmentally friendly for fabricating sensors.