Additively Manufactured Rapid Prototype Circuits with Convertible Inks

Flexible Hybrid Electronics (FHE) devices are primarily manufactured using printable inks, such as conductive/resistive and dielectric/insulative inks. Printable inks usually consist of metal nanoparticles or polymers/ceramics to produce conductive/resistive or dielectric/insulative patterns, respectively. However, various issues must be addressed when using multiple printable inks, such as solvent compatibilities and adhesion between multiple inks. The best solution is to develop one ink that can be used to fabricate both conductive/resistive and dielectrics/insulative parts. In order to fulfill this requirement, our group developed a first-generation convertible ink previously. In this project, a second-generation convertible ink was developed with superior performance compared to the first-generation convertible ink. The second-generation convertible ink was developed using silver nanoparticles combined with polyvinyl pyrrolidone and/or ceramic nanoparticles. After curing at 120 °C for 30 minutes, an insulating blanket film is left. Then, selective laser sintering can be used to create conductive/resistive patterns. The resistivity can be adjusted by varying laser sintering parameters. This convertible ink can be printed in aerosol jet printers and dispensing printers, and selective laser sintering can be performed with the inbuilt 830 nm laser in Optomec AJ5X aerosol jet printer. This technology can be used to fabricate FHE devices in remote locations where printing is not feasible. Insulating layers can be printed and can be sent to a remote location to fabricate FHE devices using a compact laser. This technology can be identified as potential FHE device fabrication technology at the International Space Station (ISS) without printing liquid inks under microgravity. Ink formulation, characterization, and fabricated FHE prototypes will be presented.