Development of 3-D Chemical Mechanical Polishing Process for Nanostructuring of Bioimplant Surfaces

This study focuses on the development of a three dimensional chemical mechanical polishing (CMP) process to induce smoothness or controlled nano-structures on the bio-implant material surfaces, particularly for an application on the dental implants. CMP helps produce implant surfaces that are cleaned from potentially contaminated surface layers by removing a nano-scale top layer during the process. Simultaneously, it creates a protective oxide film on the surface to limit any further contamination to minimize risk of infection [1]. Furthermore, the process can induce controlled surface topography. Therefore, we propose CMP as a synergistic method for nano-structuring of implant surfaces. In our earlier work, we have demonstrated that the CMP induced controlled surface roughness on the titanium based bio-materials helped control the infection resistance through formation of a self-protective titanium oxide film on the implant surfaces [2]. Yet, it is critical to be able to extent these findings to a 3-D platform to make the dental implants processed by CMP application. The 3-D CMP process is established through use of robotics and control systems by integrating a robotic arm to the sample to be polished through a force-torque sensor. This technique, once programmed, can induce the same force on the various regions of the bio-implant sample and effectively smoothen or nano-structure the alternative surfaces on the implant. Considering the wide applications [3] of the implants as dental implants, orthopedic devices, cardiac pacemakers and catheters, this new application of CMP is believed to help create a new market for the process. References: Basim, G.B., Karagoz, A., Ozdemir, Z., “Characterization of Chemically Modified Thin Films for Optimization of Metal CMP Applications”. MRS Online Proceedings, 1560 (2013) DOI: 10.1557/opl.2013.876. Basim, G.B., Ozdemir Z., Mutlu, Özal “Biomedical Applications of Chemical Mechanical Polishing" Proceedings of the International Conference on Planarization/CMP Technology, pp. 385, October 2012 Shirkhanzadeh, M., Azadegan, M., Liu, G. Q., Mater. Lett., 24 (1995) 7-12.