Flexible printed pressure sensor integrated into inner wall of a 3D tube using additive manufacturing

In this work we present the concept and first results of a flexible pressure sensor integrated into a tubular geometry. Both sensor and pressure chamber are fabricated using screen printing and stereolithography, respectively. By combining these additive techniques, we are able to rapidly design and fabricate sensor solutions for any custom geometry, such as tube and pipe vessels that are ubiquitous in industry. Pressure sensitivity is achieved by an inexpensive, commercially available carbon-filled ink mixture printed and connected on a polyimide substrate in single and double foil configuration. After insertion and sealing of the sensor element into the tube wall, we measure the resistance change under a pressure of 0 to 1 bar, achieving a sensitivity of >4% / bar.