CAREER: Laser-Induced Solvothermal Synthesis for the Direct-Write, Microscale Additive Processing of Metals and Oxides

This Faculty Early Career Development (CAREER) project contributes to the development of manufacturing methods for microscale devices containing mixed material compositions. Additive manufacturing, which is the ability to 3D-print materials of arbitrary shape, is currently revolutionizing the way in which products are made. However, most additive manufacturing methods, especially for metals and oxide materials, are conducted on the millimeter scale or larger. Small length scales are important for products such as sensors, electronics, and medical diagnostic devices which are becoming miniaturized and portable. Further, most additive manufacturing methods are tailored for fabrication of parts containing a single material and are not well-suited for parts combining multiple different materials. This research initiative will explore the use of laser-based manufacturing to address such challenges. The ability to additively manufacture microscale parts with tailored composition will enable advances in areas such as healthcare, chemical and biomedical sensing, and energy storage. This research will use techniques from multiple different fields of study, including chemistry, materials science, optics, mechanics, and thermal modeling, to tackle the manufacturing challenges from a range of angles. Educational initiatives will be pursued, including outreach to diverse students at the K-12 level, summer camp development, and curriculum innovation at undergraduate and graduate levels. The educational outreach will focus on examining how light is used in manufacturing methods.

In this research, the focal volume of a laser will be used as a high-temperature femtoliter-scale solvothermal reactor, wherein materials will be synthesized and deposited at the laser focus from fluid precursors. This method will exploit solution phase chemistry, but confine the synthesis to the microscale, thereby taking advantage of the three-dimensional control inherent in laser direct-write manufacturing. This method will be studied for processing a wide variety of inorganic materials directly from solution precursors, including metals, oxides, alloys, ceramics, and composites thereof. A key focus of the research will be on the manufacturing of high entropy oxides. Aims include synthesis of high entropy materials, characterization and modeling of the thermal reaction environment, exploration of effects of processing conditions such as laser power, scan parameters, and precursor chemistry, and investigation of parallelization and scalability for high-throughput fabrication. Educational initiatives will aim to draw connections between commonplace activities (e.g., photography) and light-enabled manufacturing methods (e.g., photolithography) such that students and the public will gain appreciation for the technological innovations that enable the fabrication of so many of the devices used in daily life.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.