Additively Manufactured Boron Nitride Coatings for Extreme Environments

The advancement of active materials, electronics, and sensors has increased the demand for nanoparticle-based printed electronics. An emerging microscale Additive Electronics Manufacturing (AEM) method to meet this demand is Aerosol Jet Printing (AJP). AJP offers high-resolution deposition for printed electronics using nanomaterial inks. Boron nitride (BN) is a nanomaterial of high interest due to its high thermal conductivity, electrical insulation, and corrosion resistance, making it well suited for extreme environments. This work focused on optimizing BN inks for AJP, which are then used to print dense, homogeneous, and cohesive BN films that insulate and protect electronic sensors in extreme environments. This requires a fundamental understanding of ink rheology and its evolution throughout the ink formulation and printing process. Particle size analysis (PSA) was used to monitor changes in particle size during ink formulation, which provided insight into dispersion stability and process optimization. Scanning electron microscopy (SEM) verified the results found in PSA and was used to optically image BN films. The findings showed a 98.87% consolidation of particle size in the ink formulation, however, dispersion instability was observed. Overall, this study developed BN films for extreme environments, analyzing ink behavior and AJP parameters.