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.

Ohmic Curing of Three-Dimensional Printed Silver Interconnects for Structural Electronics

“…The total length of the conductive path was 4 cm. SL has been regularly used in the fabrication of hybrid structural electronics [23][24][25][26][27]39,40]; so it was determined to be the logical technology to use in our experiments. As was the case in the many examples of hybrid structural electronic fabrication cited above, channels meant to guide the deposition of ink were printed on the substrate of the for the external interconnects and joined with the internal vias at the surface.…”

“…(0.6 mm) were needed for DuPont CB100 and CB102 due to the higher viscosity of these particular pastes as noted in Table 1. As mentioned above, following the procedure developed to facilitate the creation of hybrid structural electronics [23][24][25][26][27]34,39,40], channels were 3D printed on the surface to act as a guide for the manual deposition of the printable conductors. In the case of the internal via structures, the printable conductor was injected into the via.…”

3D Printed Integrated Sensors: From Fabrication to Applications—A Review

“…Th netic sensor was calibrated to output newtons, all in an effort to either log forces taken by tissue or to characterize tissue for diagnosis. The development of the int sensor was successful, demonstrated by the sensing of the resistant force by raw b Olivas et al also utilized Hall effect sensors in the creation of their 3D printe netic flux sensor system [134]. This approach combined additive manufacturing a cro dispensing, leading to very fine details in conductive traces.…”

CubeSat Fabrication through Additive Manufacturing and Micro-Dispensing

“…Olivas [8] discussed a fourth generation magnetic flux sensor system which introduced a new method of multi-surface interconnections and placement of electronics. The magnetometer was made of a cylindrical structural substrate with the circuit constructed along the non-uniform, conformal exterior surface.…”