太陽エネルギー変換及び貯蔵用表面修飾金属酸化物ナノファイバー及び薄膜に関する研究

京都大学0048新制・課程博士博士(エネルギー科学)甲第17911号エネ博第283号新制||エネ||59(附属図書館)30731京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻(主査)教授 佐川 尚, 教授 八尾 健, 教授 石原 慶一学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDGA

Chemiresistors Based on SnO2, TiO2 and SnO2/TiO2 Films for Possible Sensing of Na+ and Ca2+ ions

Semiconductor metal oxide films have been used in sensing-based applications, and they are typically prepared by vacuum deposition techniques. In this study, we used solution-processed semiconductor metal oxides to investigate their sensitivity for cations in aqueous solution. Specifically, solution-processed tin(IV) oxide (SnO 2 ), titanium dioxide (TiO 2 ) and a composite of SnO 2 /TiO 2 were deposited on fluorine-doped tin oxide (FTO) glass and these were tested for their chemiresistive properties when exposed to cationic species in solution. Techniques such as grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and the surface profiler were utilized to characterize the metal oxide films

Surface-Based Electromyography Gesture Profiling of Laparoscopic Tools Using a Wearable Sensor

This study explores surface-based electromyography (sEMG) to evaluate the effects of tool handling and fatigue on the muscle activation of laparoscopy surgeons. Specifically, the Myo Armband is used because it is a wearable, unobtrusive, and wireless sensor. Collected EMG signatures showed that more complex gestures have more active muscle groups. For the fatigued state, analysis of the signatures using the RMS feature showed that for more complex gestures, RMS increased because of muscle compensation due to fatigue. Accuracy exercise findings showed that there is a decrease in %accuracy when using an endoscope compared to when looking directly and there is a slight decrease in %accuracy once fatigue is induced. 100% accuracy cannot be reached due to awkward tool handling. Through various experiments, this study presented possible methods to evaluate the effects of tool handling and fatigue on the muscle activation of surgeons through use of sEMG. Analysis of these signatures may lead to better understanding on how specific tool design affects muscle activity and muscle fatigue, and to utilize this as a basis for a more ergonomic laparoscopic set-up and tool design

Inkjet Printing of UHF RFID Antennas Using Silver and Gold Inks

Compared with current methods, additive manufacturing processes could offer a more environment-friendly and cost-effective solution in producing long lasting RFID tags for identification and sensing applications. In this work we report the fabrication of UHF RFID antennas by inkjet printing on a flexible substrate. Silver and gold were chosen as ink materials since they are more resistant to weathering than other metals, particularly for applications that require long-term reusability. We compared the print performance of a commercial silver ink and our lab-developed gold nanoparticle (AuNP) ink on polyethylene naphthalate. The printing process for each ink is described using an adopted loop antenna design optimized for 866-868 MHz frequency range. Assembled passive and battery-assisted RFID tags using single-and double-layer sintered, printed antennas coupled with a readable UHF RFID chip showed tolerable detection distances using a commercial compact reader (with short read range specifications). Additionally, we observed a more consistent print behavior and quality, and consequently longer read ranges for the gold antennas (up to 40 cm with battery). Furthermore, the silver antennas oxidized over time resulting in decreased read ranges. Overall, our results show the viability of a printable gold RFID antenna with a tag working range that may be fit for close range non-contact reading

Combining Surface-Based Electromyography and Motion Sensing for Detection of Human Falling

The study of falling; especially for the elderly; is a very critical problem in geriatric care and medicine. This study investigated the potential role of a surface-based electromyography (sEMG) and inertial measurement unit (IMU) sensor package for analyzing and detecting humans falling. Previous studies have only relied on motion sensors only; such as accelerometers and gyroscopes; detecting falling; which completely ignores the muscular force reaction of extremities during the precise moment before a person actually falls. This experiments conducted in this study show promising results of combining the sEMG and accelerometer signals to describe the muscular activity generated as the reflex reaction of the subjects in their arms as they grab onto something to prevent the fall. Further simulations of falling were conducted at a foam pit; specifically deliberate falling and surprised falling. Similar findings were obtained in this scenario where the subjects did not have anything to grab onto upon falling; which cancan be attributed to the fact that the subjects feel the same sensation of reflex and panic whether deliberately falling or surprised falling

Development of a Novel Laparoscopic Palpation System Using a Wearable Motion-Sensing Armband

This study proposes the development of a novel palpation system for use in the laparoscopic surgery setting, which relies on a wearable motion-sensing armband worn on the palpating arm. The system is tested by prodding the laparoscopic tool on a simulated human tissue with an anomaly underneath and measuring the effects of the forces experienced by the palpating arm by recording the accelerometer data embedded in the armband. Results show that the proposed system could detect the anomalies embedded in the gelatin phantom based on the change of the amplitude of the accelerometer data. A decrease in the average peak-to-peak amplitude of accelerometer signal by as much as 32.29% was observed for the single point prodding experiment, while a decrease of up to 22.93% was observed for the raster scan experiment. The results from this feasibility experiment confirmed the potential role of the accelerometer signal in the motion-sensing armband in being able to assist laparoscopic palpation