The process of electrophoresis/dielectrophoresis of shock-synthesized nanodiamond powders on the large-area Si field emission arrays was studied. The process was found to be very sensitive to the modification of nanodiamond powder. The growth rate and film morphology of nanodiamond coatings on Si tips were investigated. Results in fabrication and testing of nanodiamond-based cold cathodes and sealed device prototypes are presented.