F. Rajabi Kouchi, N. McKibben, A. Briggs, J. Manzi, M. Busuladzic-Begic, I. Estrada, J. Eixenberger, T. Varghese, H. Subbaraman, D. Estrada
Boise State University,
Keywords: additive manufacturing, nanotechnology, and nanocrystal inks
Summary:Additive electronics manufacturing has become a promising technique for the scalable fabrication of electronic devices such as sensors, solar cells, and energy storage devices. However, the field is limited by the availability of multifunctional nanomaterial inks. For example, tailoring metal work function of printed metals is critical in achieving low contact resistance to semiconductor films, while tuning band gap, piezoelectricity, Seebeck Coefficient, and pseudo capacitance of printable inks can open up new applications in printed semiconductor devices, optoelectronics, and energy harvesting and storage devices. Here we summarize our efforts in developing, synthesizing, characterizing and formulating nanomaterial inks for additive electronic manufacturing techniques particularly as it relates to On Demand Manufacturing of Electronics. We use synthesis techniques such as ball-milling, liquid phase exfoliation, and solvothermal processes for synthesizing high-quality nanomaterials including transition metal chalcogenides, noble metals, transition metal oxides, black phosphorus, MXenes, graphene, and hexagonal boron nitride. The synthesized nanomaterials are formulated and developed into nanomaterial inks compatible with various additive electronic manufacturing techniques including screen printing, aerosol jet printing, plasma jet printing, and extrusion based writing. Detailed analysis of the material characterization, ink properties, and printing parameters for multiple printer modalities are required to optimize the fluid dynamic and properties of the inks. Additionally, various post-printing process techniques such as low-temperature photonic sintering, in-situ plasma sintering, and annealing at high temperature under nitrogen and hydrogen gas are employed for the printed nanomaterials inks in order to achieve bulk-like performance for the printed structures. Our results highlight the innovations in synthesis and formulation of nanomaterial inks for multiple printer modalities and the development of stretchable skin electronics, piezoelectric surface acoustic wave thermometers, and flexible thermoelectric energy harvesters for applications in extreme environments.