Increasing the Reliability of 3D Printing a Wi-Fi Sensor Device

Abstract

Printed electronics and 3D printing have proved their viability for manufacturing functional devices. The state of the art is now at a crossroads where yield, reliability, survivability, and longevity improvements will govern its continued success in manufacturing. Currently, 3D printed electronics demonstration parts are either grossly oversized or are meticulously fabricated and involve significant human interaction and repair and ultimately have low manufacturing yield. Presented here are techniques for improving manufacturing yield. Coefficient of thermal expansion (CTE) mismatch problems frequently occur in devices with heterogeneous materials such as bulk metals, thermoplastics, thermosets, conductive pastes and inks, and pourable dielectrics. Controlling the interfaces between these materials in new and creative ways is key to solving these problems during manufacturing and lifecycle. Selecting materials with good properties such as adhesion, surface energy, flexibility, conductivity, and dielectric properties is the path forward to excellence in this field. Certain improvements in the design of 3D printed electronic devices (demonstrated here) show improved ruggedness. A long-lasting 3D printed electronic device that has been operating 24/7 for 21,000 hours is shown, and the techniques of its design and fabrication are described in detail. Several testing procedures evaluate the performance of the devices. Microscope photos show key problem areas, solutions are implemented, and material selections are presented. Overall device function is monitored wirelessly before, during, and after temperature changes.