New Low-Frame-Rate Compensating Pixel Circuit Based on Low-Temperature Poly-Si and Oxide TFTs for High-Pixel-Density Portable AMOLED Displays

A new low-frame-rate active-matrix organic light-emitting diode (AMOLED) pixel circuit with low-temperature poly-Si and oxide (LTPO) thin-film transistors (TFTs) for portable displays with high pixel density is reported. The proposed pixel circuit has the excellent ability to compensate for the threshold voltage variation of the driving TFT (ΔVTH_DTFT). By the results of simulation based on a fabricated LTPS TFT and a-IZTO TFT, we found that the error rates of the OLED current were all lower than 2.71% over the range of input data voltages when ΔVTH_DTFT = ±0.33 V, and a low frame rate of 1 Hz could be achieved with no flicker phenomenon. Moreover, with only one capacitor and two signal lines in the pixel circuit, a high pixel density and narrow bezel are expected to be realized. We revealed that the proposed 7T1C pixel circuit with low driving voltage and low frame rate is suitable for portable displays.

Flexible Temperature Sensors

Temperature reflects the balance between production and dissipate of heat. Flexible temperature sensors are primary sensors used for temperature monitoring. To obtain real-time and accurate information of temperature, different flexible temperature sensors are developed according to the principle of flexible resistance temperature detector (FRTC), flexible thermocouple, flexible thermistor and flexible thermochromic, showing great potential in energy conversion and storage. In order to obtain high integration and multifunction, various flexible temperature sensors are studied and optimized, including active-matrix flexible temperature sensor, self-powered flexible temperature sensor, self-healing flexible temperature sensor and self-cleaning flexible temperature sensor. This review focuses on the structure, material, fabrication and performance of flexible temperature sensors. Also, some typical applications of flexible temperature sensors are discussed and summarized.

MEMS development focusing on collaboration using common facilities: a retrospective view and future directions

I have been developing MEMS (microelectromechanical systems) technology and supporting the industry through collaboration. A facility was built in house on a 20 mm square wafer for use in prototyping MEMS and ICs (integrated circuits). The constructed MEMS devices include commercialized integrated capacitive pressure sensors, electrostatically levitated rotational gyroscopes, and two-axis optical scanners. Heterogeneous integration, which is a MEMS on an LSI (large-scale integration), was developed for sophisticated systems using LSI made in a foundry. This technology was applied for tactile sensor networks for safe robots, multi FBAR filters on LSI, active-matrix multielectron emitter arrays, and so on. The facility used to produce MEMS on 4- and 6-inch wafers was developed based on an old semiconductor factory and has been used as an open hands-on access facility by many companies. Future directions of MEMS research are discussed.

Origin of MMP-8 and Lactoferrin levels from gingival crevicular fluid, salivary glands and whole saliva

Background Pathologically elevated levels of matrix metalloproteinase-8 (MMP-8) and Lactoferrin in oral fluids have been associated with the presence of gingivitis/periodontitis. This study aimed to assess the origin of MMP-8 and Lactoferrin in periodontitis patients and to identify the degree to which conventional clinical parameters correlate with their presence. Methods A total of ten periodontitis and ten healthy patients were included in this study. Whole saliva (stimulated and unstimulated), parotid/sublingual glandular fluid and gingival crevicular fluid from pockets and sulci were tested for MMP-8 and Lactoferrin and protein concentrations were quantified using an ELISA assay. Clinical parameters were checked for potential associations with MMP-8 and Lactoferrin levels. Results Periodontal patients presented higher concentrations of MMP-8 and Lactoferrin in pockets than other sources (P = 0.03). Lactoferrin measurement was higher in the parotid compared to sublingual glandular fluid in periodontitis patients (P = 0.03). Increased probing pocket depth was positively correlated with high MMP-8 and Lactoferrin levels. Conclusions Periodontal pockets appear to be the major source of active matrix metalloproteinase and Lactoferrin, which also may also enter the oral cavity through the salivary glands. Since clinically healthy sites in periodontitis patients also had elevated biomarker levels, gingival crevicular fluid biomarker testing may be more predictive of future tissue breakdown than conventional clinical parameters.