Development of taste sensor system with the high durability by transition metal oxide semiconductor thin film

在本研究中，我们开发了高耐用性的饮料识别系统(DRS)。铁氧体的电学性质随其表面吸附的某种分子和离子而变化，因此可以像味觉传感器一样应用。将锰锌铁氧体磁性薄膜(FMF)应用到饮料识别传感器中，构建了磁敏传感器，并在Al_2O_3衬底上通过溅射或真空沉积及热处理工艺制备了磁性薄膜。耐用性非常高，因为FMF是金属氧化物。当食物中的各种风味成分附着在FMF上时，FMF表面的电动势会发生变化。因此，FMF可以识别食物。该多通道识别系统通过制备条件结合具有不同电学性质的多个FMF传感器，可以从输出模式中清晰地区分各种饮料的种类。DRS的输出模式表明了对不同基本味觉材料的不同反应。因此，DRS似乎可以识别各种饮料。对于不同的饮料，DR进行了区分测试。例如，样品饮料被分成6种类型(红酒、白葡萄酒、乌龙茶、绿茶、运动饮料和矿泉水)，每组分别包括三个品牌(_&lt；1&gt；3)。结果表明，同类型饮料的测定值分布较近，每天一次重复测试一周，测定值的误差约为7~10%。当考虑被测样品的分布时，DRS的传感似乎表现出较高的重复性。对各种样品进行了大约10个月的辨别试验。作为饮料识别系统的传感器，亚铁磁性半导体薄膜没有出现退化现象。经确认，该饮品识别系统已长期使用。

In this research, we developed the Drink Recognition System (DRS) with high durability. The electrical property of ferrite changes according to a sort of a molecule and an ion absorbed physically on its surface, so it can be applied like the taste sensor. We applied the MnZn ferri magnetic thin film (FMF) to the drink recognition sensor and constructed DRS.The FMF is prepared on Al_2O_3 substrate by the sputtering or the vacuum deposition and the annealing process. The durability is very high, since FMF is the metal oxide. When various taste components included in food adheres to the FMF, electromotive force on surface of the FMF changes. Therefore, the FMF can recognize the foods. The multi channel recognition system combined with the plural FMF sensors having different electrical properties by the preparation conditions can clearly distinguish the kinds of various drinks from output patterns. The output patterns of DRS indicate different response to each fundamental taste materials. Therefore, it seems that the DRS can recognize various drinks.For various drinks, discrimination test were carried out by the DRS.For example, the sample drinks are grouped in 6 types (red wine, white wine, oolong tea, green tea, sports drink and mineral drink), and three brands (_<1〜>3) are included for each groups, respectively. It is shown that the outputs of DRS for the drinks of the same type are distributed in a close place, respectively.In the repeat test throughout a week with the one time measurement every day, the error of an output of DRS was about 7〜10%. The sensing due to DRS seems to show comparatively high reproducibility, when the distribution of measured sample is considered.The discrimination test for various samples was carried out for about 10 months. The degradation of ferrimagnetic semiconductor thin film as a sensor of the drink recognition system was not appeared. It was confirmed that the drink recognition system was stood long-term use.