Structural Electronics through Additive Manufacturing and Micro-Dispensing

Abstract

Implementing electronics systems that are conformal with curved and complex surfaces is difficult if not impossible with traditional fabrication techniques, which require stiff, two dimensional printed circuit boards (PCB). Flexible copper based fabrication is currently available commercially providing conformance, but not simultaneously stiffness. Consequently, these systems are susceptible to reliability problems if bent or stretched repeatedly. The integration of Additive Manufacturing (AM) combined with Direct Print (DP) micro-dispensing can provide shapes of arbitrary and complex form which incorporate 1) miniature cavities for insetting electronic components and 2) conductive traces for electrical interconnect between components. The fabrication freedom introduced by AM techniques such as stereolithography (SL), ultrasonic consolidation (UC), and fused deposition modeling (FDM) have only recently been explored in the context of electronics integration. Advanced dispensing processes have been integrated into these systems allowing for the introduction of conductive inks to serve as electrical interconnect within intricately-detailed dielectric structures. This paper describes a process that provides a novel approach for the fabrication of stiff conformal structures with integrated electronics and describes several prototype demonstrations: a body conformal helmet insert for detection of Traumatic Brain Injury (TBI), a 3D magnetic flux sensor with LED indicators for magnitude and direction and a floating sensor capable of detecting impurities in water while maintaining orientation through density gradients.