In Vitro Bioactivity of Atomic Layer Deposited Titanium Dioxide on Titanium and Silicon Substrates


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A non-bioactive implant device can easily be changed to in vitro bioactive with a thin coating of crystalline TiO2. This crystalline coating can be deposited very thin with great step coverage at a low temperature with Atomic Layer Deposition (ALD). An anatase TiO2 coating was built up atomic layer by atomic layer using TiI4 and H2O as precursors in a hot wall furnace. Several hundreds of cycles resulted in a 10-30nm well defined TiO2 of anatase phase on both Si and Ti substrates. These coatings were shown to be bioactive when immersed in simulated body fluid in vitro, as hydroxyapatite (HA) formed on the surface. The surface roughness of the substrates affected the adhesion of the HA. The adhesion was low on the smooth Si but much better on the 100 times rougher Ti. The ALD technique is promising for coating substrates of all shapes with bioactive crystalline TiO2 at a low temperature.



Key Engineering Materials (Volumes 361-363)

Main Theme:

Edited by:

Guy Daculsi and Pierre Layrolle




J. Heinrichs et al., "In Vitro Bioactivity of Atomic Layer Deposited Titanium Dioxide on Titanium and Silicon Substrates", Key Engineering Materials, Vols. 361-363, pp. 689-692, 2008

Online since:

November 2007




[1] Brunette D, Tengvall P, Textor M, Thomsen P (2001), Titanium in medicine, Springer Germany (Ed Brunette D).


[2] Svetina M, Colombi Ciacchi L, Sbaizero O, Meriani S, De Vita A, Deposition of calcium ions on rutile (110): A first-principles investigation, Acta materialia 49 (2001) 2169-2177.


[3] Kim H-M, Himeno T, Kokubo T, Nakamura T, Process and kinetics of bonelike apatite formation on sintered hydroxyapatite in a simulated body fluid, Biomaterials 26 (2005) 4366- 4373.


[4] Gu Y W, Tay B Y, Lim C S, Yong M S, Biomimetic deposition of apatite coating on surface-modified NiTi alloy, Biomaterials 26 (2005) 6916-6923.


[5] Holvik N D, Elam J W, Linderman R J, Bright V M, George S M, Lee Y C, Atomic layer deposited protective coatings for micro-electrochemical systems, Sensors and Actuators 103 (2003) 100.


[6] Aarik J, Aidla A, Uustare T, Kukli K, Sammelselg V, Ritala M, Leskelä M, Atomic layer deposition of TiO2 thin films from TiI4 and H2O, Applied Surface Science 193 (2002) 277-286.