Flexible capacitive pressure sensor based on electrically assisted micro-nanoimprinting

Flexible pressure sensors are evolving towards higher precision, larger areas, multi-sensing capabilities, increased resolution, and integration, imposing greater demands on the fabrication processes of flexible sensor devices. This study proposes a fully printed fabrication process utilizing electric field-assisted 3D micro-nanojet printing technology to manufacture capacitive sensors. Additionally, it designs sensor simulation studies based on hemispherical structures, cubic structures, and various microstructure arrangement densities to guide the preparation of capacitive pressure sensors. By utilizing PDMS mixed with 10% graphene material to print the dielectric layer with microstructures and conductive silver adhesive to print the electrode layer, the all-printing process significantly enhances the fabrication efficiency of flexible capacitive pressure sensors. The fabricated sensor achieves a maximum sensitivity of 0.7826 kPa⁻¹ with a response time of 90 ms and a recovery time of 50 ms. It exhibits excellent responsiveness and stability during 4000 cycle tests, validating that the flexible capacitive pressure sensor, based on micro-nano-3D printing, can enhance the fabrication efficiency of flexible capacitive sensors and deliver outstanding performance.