Patent ID: 7807216

Claim:
A process for depositing dense, thick piezoelectric composite coatings with uniform microstructure on an electrode layer coated silicon substrate comprising the steps of: preparing an organo-metallic sol-gel solution of Pb 1+y (Zr x Ti 1−x )O 3 (PZT) of desired concentration and chemical formula; dispersing selected pre-formed nanocrystalline piezoelectric particles with grain sizes less than 100 nm into said sol-gel solution of PZT to form a uniform stable dispersion, slurry or paste, said pre-formed nanocrystalline piezoelectrical particles selected from the group consisting of PZT, PLZT, Pb(Mg 1/3 Nb 2/3 )O 3 (PMN), Pb(Zn 1/3 Nb 2/3 )O 3 (PZN), (Ba,Sr)TiO 3 (BST), PbTiO 3 (PT), BaTiO 3 (BT), PMN-PT, PZN-PT, and any other composition with good piezoelectric properties; depositing said stable dispersion, slurry or paste on an electrode layer coated silicon wafer by spin-coating or screen-printing to form a green body; and heating said green body at a temperature from 650° C. up to 800° C. so as to produce dense, thick piezoelectric composite coating with thickness of between 1 to 100 μm on said silicon substrate, said composite coating possessing grain sizes less than 100 nm and final densities up to 99% of the theoretical limit for such composites.