SusCheM: Directed Covalent Assembly of Nanodiamonds into Films for MEMS Applications

Louisiana Tech University, Ruston LA

Investigators

Abstract

Diamond thin films play an important role in many established and emerging areas of technology including manufacturing tools, protective coatings, and high power electronics due to their increased resistance to wear, chemical stability, low coefficient of friction, low coefficient of thermal expansion, wide optical transparency, biocompatibility, and tunable conductivity. For similar reasons, diamond thin films have also started attracting attention from researchers for use in microelectromechanical systems (MEMS) such as sensors and actuators. However, besides performance the scalability, sustainability, and cost of these films are also factors that influence their viability for widespread use. This award supports fundamental research to provide needed knowledge for the development of a novel diamond film growth process that: (1) can be performed virtually on any substrate, including metals, oxides, and plastics, (2) is economical due to low cost and ready availability of the raw material, (3) poses lower health hazards and is environmentally safe, and (4) can be integrated with standard semiconductor technology. Such low cost, scalable diamond films with tailorable physical properties will enable broad impact in energy, manufacturing, healthcare, sensors, electronics, and other important applications, thus providing a positive impact on the U.S. economy and society. In addition, this multi-disciplinary approach involving research in chemistry, materials science, manufacturing, and engineering will provide a significant impact on broadening participation of minorities in research, and incorporating nanomaterial manufacturing concepts in K-12 curriculum. The concept of directed covalent assembly of nanodiamonds using versatile, room-temperature chemistry to form conformal and compact films will pave the way to a novel class of sustainable coatings for MEMS. The full application potential of covalently assembled nanodiamond films can be achieved by overcoming the scientific barrier of tuning its physical properties (mechanical, thermal, and optical) which are directly linked to the level and distribution of porosity in the film micro-/nanostructure. This research seeks to fill the knowledge gap on the mechanism(s) of porosity reduction through precise control over nanodiamond aggregate size during film fabrication as well as post-fabrication anneal. The research team will characterize porosity distribution and the associated physical properties using state-of-the-art materials characterization methods. Further, microfabricated devices will be made with the nanodiamond films as a vehicle to demonstrate its integration into MEMS, to facilitate quantification of physical properties such in-plane and cross-plane thermal conductivity, and to correlate these findings to the nanodiamond aggregate sizes used during the direct covalent assembly process.