Student: Matthew Marander, graduate student in Materials Science and Engineering, Iowa State University,
Faculty Advisor: Shan Jiang
Development of Ceramic Inks for the Electrohydrodynamic Inkjet Printing of Functional Electronic Devices
Resupply missions for spacecraft suffer from limited cargo space, requiring prioritization of materials. Improvements to supply availability and variety could be made with the production of devices on demand where raw material is transported instead. This would allow for the freedom to produce a device independently, making the most out of limited cargo space. Electrohydrodynamic EHD inkjet printing is a printing technique that uses an electric field to jet the ink onto a substrate. The electric field has the effect of pulling the ink onto the working substrate, allowing the printer to function effectively in a low-gravity environment, as well as focusing the ink into a stream smaller than the printhead nozzle, allowing for micron-level resolution. This printing technique has different ink requirements than more traditional inkjet printing, and, being relatively new, there are no commercially available inks for use in EHD printing. Prior art examines conductive materials (silver, gold, copper, etc.) but not non-metallic materials, which provide broader functionality to electronics, giving the ability to produce dielectric and semiconductor devices. My current research involves the development of a reactive zinc oxide ink for the printing of transistors and memory devices. Motivation towards this approach, as opposed to a more conventional nanoparticle dispersion, was brought about by the potential of higher levels of printing resolution being unhampered by particle size and the ability to deposit ink within already fabricated nanoscale silicon substrates. Final device functionality is heavily dependent upon materials synthesis and processing. Electronic properties and device type, for example, may be selected through the level of crystallinity of the material or lack thereof (amorphous). The utilization of multiple materials to create a final device (a metallic ink to produce a conductive pattern and a ceramic ink to provide functionality) and long-term goals of utilization on the International Space Station necessitate the development of an ink to deposit a ceramic layer that can be processed at a low temperature.