The objective of this work is the study and characterization of anodized aluminum oxide as a pH sensor. Sensing films were fabricated by anodic oxidation, a process which is low cost, in which it is simple to manufacture and mass produce films at room temperature, in which it is easy to control the variation in film resistance. The films have a good linear sensitivity, approximately 56 mV/pH from pH 4 to 10 when an instrumentation amplifier is used as the read out circuit. This study indicates that the type of aluminum substrate affects the sensing characteristics. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis show that aluminum oxides on different aluminum substrates formed by anodic oxidation have various acid-base characteristics. Extended-gate field-effect transistor (EGFET) sensing films formed when the predominant surface plane of the aluminum oxide is (012) have a linear sensitivity.

The purpose of this study was to develop novel nanoscale biosensors using titania nanotubes (TNTs) made by anodization. Titania nanotubes were produced on pure titanium sheets by anodization at room temperature. In this research, the electrolyte composition ethylene glycol 250 mL/NH4F 1.5 g/DI water 20 mL was found to produce the best titania nanotubes array films for application in amperometric biosensors. The amperometric results exhibit an excellent linearity for uric acid (UA) concentrations in the range between 2 and 14 mg/dL, with 23.3 (μA·cm−2)·(mg/dL)−1 UA sensitivity, and a correlation coefficient of 0.993. The glucose biosensor presented a good linear relationship in the lower glucose concentration range between 50 and 125 mg/dL, and the corresponding sensitivity was approximately 249.6 (μA·cm−2)·(100 mg/dL)−1 glucose, with a correlation coefficient of 0.973.

The objective of this work is the study and characterization of anodized indium tin oxide (anodized-ITO) as a sodium ion selective electrode and differential structures including a sodium-selective-membrane/anodized-ITO as sensor 1, an anodized-ITO membrane as the contrast sensor 2, and an ITO as the reference electrode. Anodized-ITO was fabricated by anodic oxidation at room temperature, a low cost and simple manufacture process that makes it easy to control the variation in film resistance. The anodized-ITO based on EGFET structure has good linear pH sensitivity, approximately 54.44 mV/pH from pH 2 to pH 12. The proposed sodium electrodes prepared by PVC-COOH, DOS embedding colloid, and complex Na-TFBD and ionophore B12C4, show good sensitivity at 52.48 mV/decade for 10−4 M to 1 M, and 29.96 mV/decade for 10−7 M to 10−4 M. The sodium sensitivity of the differential sodium-sensing device is 58.65 mV/decade between 10−4 M and 1 M, with a corresponding linearity of 0.998; and 19.17 mV/decade between 10−5 M and 10−4 M.

In this paper, we introduce a new type of termination structure utilizing semi-insulating polycrystalline silicon (SIPOS) structures in conjunction with P − junction extension in order to reduce the area of termination device structure and increase the breakdown voltage. In SIPOS structures, one high-resistance layer is deposited between electrodes on two terminals such that the voltage between two electrodes is linearly distributed instead of the original nonlinear distribution. Compared to a traditional termination structure device (with a length of 180 μm and a breakdown voltage at 570 V), the optimal design of the new type of termination structure will lead to an increase of 40 V in the breakdown voltage and a 22.2% area reduction. From the perspective of device fabrication, it has been proven that the new type of termination structure indeed consumes less area while simultaneously realizing an enhanced device breakdown voltage as high as 710 V and a specific on-resistance at 137 mΩ · cm 2 , which is consistent to the simulation results.

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