Inkjet printing of nanodiamond suspensions in ethylene glycol for CVD growth of patterned diamond structures and practical applications

Fabrication of patterned diamond structures in an inexpensive way is desirable for a variety of practical applications. Inkjet printing is a well-developed and inexpensive process by which liquid ink, as well as solid suspensions in a properly formulated solution, can be applied in a precise quantity and at selected locations on a rigid or flexible substrate. In this work, nanodiamond suspensions in ethylene glycol were used as inks for the printing of patterned nanodiamond particles on substrates. By utilizing inks with optimized nanodiamond suspensions, high number density of diamond nanoparticles were laid down directly by inkjet printing to form almost continuous nanodiamond films of designed patterns on a substrate. A brief chemical vapor deposition process that lasted for 15 to 20 min or so was adequate for the further growth of nanodiamond seeds to form a continuous nanocrystalline diamond film. This process allows inexpensive seeding of diamond in selected areas as well as possible formation of 1-D, 2-D, and 3-D nanodiamond structures. Details of the inkjet printing process and its potential applications will be reported.