TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further involves depositing the seed layer on the hydrogen membrane cathode electrode by one of spin-coating and dip-coating HAP particles (preferably depositing seed layer on non-metallic or pure palladium hydrogen membrane cathode electrode electrochemically). The method involves reducing an amount of evolved hydrogen at the cathode electrode by applying an electrical current less than or equal to 10 (mA/cm2) or limiting the deposition time to 5 to 1 minute. During secondary crystallization, controlling supersaturation of HAP to mediate crystal nucleation and growth involves one of a calcium ion chelator and pH regulator. During tertiary crystallization, controlling the c-axis/a-axis growth involves adding a cationic surfactant (preferably cetylpyridinium chloride) during the hydrothermal growth of the HAP film and varying the ratio of calcium to phosphorus. The method involves controlling the thickness of the HAP thin film to a thickness of less than or equal to 10 microns by at least one of limiting the electrochemical deposition time 5 to 1 minute and creating a higher molar ratio of calcium to phosphate during at least one of the hydrothermal depositions. The method involves adding a crystal growth modifier to alter the growth rate of the crystal a-axis relative to the crystal c-axis. Preferred Components: The calcium ion chelator comprises ethylenediaminetetraacetic acid (EDTA) and bis(2-ethylhexyl) sulfosuccinate. The pH regulator comprises one of urea and hexamethylenetetramine. During tertiary crystallization, controlling the c-axis/a-axis growth is obtained by a crystal growth modifier selected from tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium bromide, tetrabutylammonium bromide, tetrapropylammonium bromide, tetrahexylammonium bromide, tetraoctylammonium bromide, triethanolamine, trimethyl(tetradecyl)ammonium bromide, benzyltriethylammonium chloride, benzyldimethyldodecylammonium chloride, poly(diallyldimethylammonium chloride), 1-ethyl-2-methylquinolinium iodide and cetyltrimethyl ammonium bromide.