Preparation and Characterization of RF Sputtered Thin Film TiO2 on NiTi

Abstract: Nowadays, the application of biosensors in the food and chemical industries, agriculture, animalfarming, and especially in the medical diagnosis, has been developed enormously. The use of smartmaterials and nanotechnology in biosensors has also been increased their sensitivity and accuracy. One ofthese smart alloys is the Nickel-Titanium compound, nitinol, which has become more prominent within thehuman body applications due to its high biocompatibility that can be produced. One of the challenges ofusing this alloy inside the body is its corrosion process in the vicinity of the bloodstream, resulting in therelease of nickel ions in the blood. One of the most effective methods for increasing the resistance of thealloy to corrosion is the use of various coatings, especially TiO2.The main objective of this study is to investigate the behavior of TiO2-coated NiTi alloy for biosensingapplications. To achieve this, microstructure and thermal properties of TiO2-coated NiTi have beeninvestigated using Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC)respectively. The corrosion behavior of the samples was also observed in two different solutions ofSimulated Body Fluid (SBF) and Human Serum using Electrochemical Impedance Spectroscopy (EIS).The results of the DSC test showed that TiO2 coating does not have any effect on the memory behavior ofNiTi. Also, the results of the EIS test are shown increasing the thickness of TiO2 is resulted in increasedcorrosion resistance at both Serum and SBF solutions.

Keywords:

NiTi , Shape memory alloy , TiO2