Synthesis and electro-optical properties of carbazole-substituted pyrene derivatives.

Mono and dicarbazole-substituted pyrene derivatives, 9H-carbazol-9-ylpyrene (MCzP) and 1,6-di(9H-carbazol-9-yl)pyrene (DCzP), with dual-purpose function as a blue emitting and charge transporting layer in organic light emitting diodes, were synthesized and characterized. These series of molecules consisted of an electron donating (D) carbazole and an electron accepting (A) pyrene in D-A and D-A-D shapes. Non-doped blue electroluminescent devices with the configurations of ITO (150 nm)/alpha-NPD (30 nm)/DCzP (40 nm)/LiF (1 nm)/Al (150 nm) (D1) and ITO (150 nm)/2-TNATA (15 nm)/alpha-NPD (20 nm)/DCzP (40 nm)/BCP (15 nm)/Alq3 (10 nm)/LiF (1 nm)/Al (120 nm) (D2) were fabricated. D1 and D2 devices showed blue emission at 492 nm and 488 nm, and maximum luminance of 840 and 7560 cd/m2 obtained at 13 V and 15 V, respectively.

Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal.

We studied the effect of light-induced gliding of the easy axis of dye-doped nematic liquid crystal on an aligning polymer surface. The observed drift of the easy axis is over tens of degrees and is caused by light-induced anisotropic adsorption and/or desorption of dye molecules on or from the aligning layer in the presence of light-induced bulk torque. We present a theoretical model that explains the experimental data in terms of the light-induced changes of the adsorbed dye molecules angular distribution due to their exchange with the dye molecules from the liquid crystal bulk.

Experimental evaluations of wearable ECG monitor.

Healthcare industry is changing with ubiquitous computing environment and wearable ECG measurement is one of the most popular approaches in this healthcare industry. Reliability and performance of healthcare device is fundamental issue for widespread adoptions, and interdisciplinary perspectives of wearable ECG monitor make this more difficult. In this paper, we propose evaluation criteria considering characteristic of both ECG measurement and ubiquitous computing. With our wearable ECG monitors, various levels of experimental analysis are performed based on evaluation strategy.