Graphene dots precisely controlled in size are interesting in nanoelectronics due to their quantum optical and electrical properties. However, most graphene quantum dot (GQD) research so far has been performed based on flaketype graphene reduced from graphene oxides. Consequently, it is extremely difficult to isolate the size effect of GQDs from the measured optical properties. Here, we report the sizecontrolled fabrication of uniform GQDs using self-assembled block copolymer (BCP) as an etch mask on graphene films grown by chemical vapor deposition (CVD). Electron microscope images show that as-prepared GQDs are composed of mono-or bilayer graphene with diameters of 10 and 20 nm, corresponding to the size of BCP nanospheres. In the measured photoluminescence (PL) spectra, the emission peak of the GQDs on the SiO 2 substrate is shown to be at ∼395 nm. The fabrication of GQDs was supported by the analysis of the Raman spectra and the observation of PL spectra after each fabrication step. Additionally, oxygen content in the GQDs is rationally controlled by additional air plasma treatment, which reveals the effect of oxygen content to the PL property.

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In order to detect blood volume changes, we proposed the new magnetic plethysmographic sensor using timevarying magnetic fields, and thereby, measuring the change of impedance of exciting coil. The change of coil impedance was proportional to the change of blood volume passing through a volume-of-interests, which inductively coupled with exciting coil. In order to verify the feasibility of the proposed method, photo-plethysmographic and magneto-plethysmographic (MPG) signals were recorded from the index and middle finger of the left hand simultaneously. Comparison of the proposed sensor signals with ultrasound Doppler blood flow velocity recordings shows the excellent correlation (r = 0.9355, p < 0.01) and the RR intervals derived from electrocardiograph and MPG signals showed a very high degree of correlation (r = 0.9823, p < 0.01).Index Terms-Blood flow, blood volume, magnetic plethysmography, time-varying magnetic fields.

The research on amorphous indium–gallium–zinc oxide (IGZO) Schottky contacts has received much attention for various electronic applications due to their high uniformity, excellent electrical properties, and large band gap. However, noble metal/IGZO Schottky contact is often challenged by chemical reaction at the interface between the noble metal and IGZO. Herein, we present a strategy to form the Schottky barrier via a defect-induced physical interface modification (DIPIM) process using defect engineering of the insulator. We show that high-quality IGZO can be formed for high-performance Schottky contact without chemical reaction by inserting defect-induced Al2O3 between Pd and IGZO. DIPIM ensures an oxygen-rich environment in IGZO at the Pd/IGZO interface, reducing the level of oxygen vacancy defects and suppressing the In metal reduction. Using this process, we improved the Pd/IGZO Schottky characteristics such as the high rectifying ratio by suppressing the leakage current. Furthermore, the Schottky barrier is consistent with the theoretical value of the Schottky–Mott relationship. We believe that this strategy not only provides a suitable platform for high-performance IGZO Schottky contact by preventing the chemical interaction between the noble metal and IGZO but also accelerates the development of practical IGZO Schottky contact application devices.

-In this paper, through a digital potentiometer and exponentially weighted moving average filter, pulse and PPG waveform measurable device was fabricated in radial artery. If this device is not proper about signal size in analog part, MCU can judge easily by adjusted amplification through digital potentiometer, using exponentially weighted moving average filter is able to filter out more clear value of ADC. I presumed pulse rate as value of measuring time between point of maximum contraction from sensing signal in radial artery of wrist. Therefore, this means can measure stable pulse rate and PPG waveform, finger as well as radial artery, whether signal size of each person is different finger as well as radial artery.

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This paper describes a basic study on the measurement of return loss and change in Smith chart using a microstrip patch antenna (MPA) with concentration transition to perform non-invasive blood glucose measurements. To evaluate blood glucose level changes in the human body, the concentration of measurements was changed 10 times to an equivalent of 100 mg/dL in a range of 0-1000 mg/dL to reflect a concentration of 400 mg/dL, which is the fatal level of diabetes. Five types of MPAs were fabricated that formed resonant frequencies in the 1, 2, 3, 4, and 5 GHz bands, and were used in the experiment. Each MPA constituted a sharp narrow band characteristic and induced a large change in return loss. By measuring the return loss and Smith chart to evaluate the concentration change at resonant frequencies, the return loss was observed to change by an average of 0.058 dB for every 100 mg/dL change, and the impedance magnitudes and phase angles analyzed through the Smith chart were observed to have a certain tendency, which confirmed that they were changed. This study shows that for performing non-invasive measurements of blood sugar level, measuring the change in return loss can provide a more stable and reliable measurement compared to the two methods that are simultaneously used to view the samples.

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