A Real-Time Process Diagnostic to Support Reliability, Control, and Fundamental Understanding in Aerosol Jet Printing

Aerosol jet printing is a compelling technology for hybrid electronics, combining digital and noncontact patterning with broad materials compatibility, resolution as fine as approximate to 10 microns, and a high standoff distance of 1-5 mm. Despite its growing popularity in research environments, a robust process understanding and improved manufacturing control are essential for achieving the reliability and predictability required for broader adoption in advanced applications. Herein, recent developments in process monitoring using in-line light scattering measurements are discussed, including their mechanistic foundations, experimental validation, relevance for process control and reliability, and value as a diagnostic tool for fundamental studies. Experimental measurements confirm the correlation between measured light scattering and deposition rate. Building on this platform, feedback from the real-time measurement is coupled with printer software to support automated closed-loop control via a simple proportional-integral-derivative software control loop. Combined with the utility of these measurements as a diagnostic to accelerate ink formulation and support fundamental process science experiments, this in-line measurement provides a useful tool to improve print reliability with the potential to advance the adoption and capabilities of this method in conformal, flexible, and hybrid electronics applications. Real-time process monitoring using light scattering offers broad utility for aerosol jet printing. This value spans process control and quality monitoring in production environments, material and process development for rapid prototyping, and an in-line diagnostic tool for fundamental studies. This Perspective traces the development of this technology and offers a commentary on its outlook and limitations.image (c) 2023 WILEY-VCH GmbH