Advancing Materials Discovery and Electronics Fabrication via Aerosol Jet Printing

Aerosol jet printing (AJP) is a versatile additive manufacturing (AM) method that can deposit a wide range of organic and inorganic materials with high spatial resolution of about 10 µm. Over the past decade, AJP has been extensively applied to fabricate electronics, sensors, and energy conversion and storage devices. However, numerous potential fields remain unexplored. This thesis presents a novel aerosol-based high-throughput combinatorial printing (HTCP) method to accelerate materials discovery and a non-thermal plasma-integrated AJP to print electronics on temperature-sensitive substrates such as textiles, plants, and hydrogels. For the applications of high-throughput materials discovery, the unique combinatorial AJP system realizes in situ mixing of multiple aerosolized inks and fast modulation of the mixing ratio on-the-fly during the printing process. Consequently, combinatorial materials with compositional gradients at microscale spatial resolution were achieved. A series of high-throughput printing strategies and applications, including combinatorial doping and functional grading, were demonstrated. A functionally graded polymer-based solid-state electrolyte with gradient compositions along the film thickness direction was prepared. The electrolyte delivers enhanced energy storage performance when used in the high voltage lithium metal batteries. For the applications of printing electronics on temperature-sensitive substrates, non-thermal plasma was introduced to the AJP system. The plasma jet can convert aerosolized inks into highly conductive metal patterns at room temperature without damaging the temperature-sensitive substrates. This method was first applied to the fabrication of gold electrodes on permeable textiles for human health monitoring. As a demonstration, glucose and hydrogen peroxide sensors were fabricated on nylon fabric for human health monitoring. Then, the plasma integrated AJP was used to print gold electrodes on leaves with barbed surface for plant health monitoring. Lastly, this method was employed to pattern bioelectronics on hydrogels. The use of in situ plasma treatment produced electrodes with high conductivity, strong bonding, and excellent stretchability.