Yuji Nagasaka

Learn More
A novel micro optical diffusion sensor (MODS) has been developed that enables high-speed, on-site sensing with a small sample volume and without the use of additives. The diffusion coefficient can be measured by observing the mass diffusion process of the concentration distribution generated by laser-induced dielectrophoresis. In this paper, we propose a(More)
We have developed a novel micro optical diffusion sensor (MODS) with a newly proposed comb-driven-micro Fresnel mirror (CD-MFM) scanner to detect structural changes in biological samples. By controlling the fringe spacing of the excitation laser beam, we can tune the decay time to obtain quick and precise measurements. In this study, the pre-tilted mirror(More)
We have developed a novel nanoscale temperature-measurement method using fluorescence in the near-field called fluorescence near-field optics thermal nanoscopy (Fluor-NOTN). Fluor-NOTN enables the temperature distributions of nanoscale materials to be measured in vivo/in situ. The proposed method measures temperature by detecting the temperature dependent(More)
A novel micro optical viscosity sensor (MOVS), by laser-induced capillary wave method enabling us non-contact, short-time (several hundreds of nano seconds), and small sample volume (several tens of micro litters) in situ/in vivo measurement, is reported in this paper. The microfabricated MOVS chip consists of two deep trenches holding photonic crystal(More)
This paper reports the development of an electrothermal microelectromechanical systems (MEMS) mirror with serpentine shape actuators. A micro Fresnel mirror with fringe-spacing tunability is required to realize a compact and high-speed diffusion sensor for biological samples whose diffusion coefficient changes significantly because of a conformational(More)
A novel local temperature measurement method using fluorescence near-field optics thermal nanoscopy (Fluor-NOTN) has been developed. Fluor-NOTN enables nanoscale temperature measurement in situ by detecting the temperature-dependent fluorescence lifetime of CdSe quantum dots (QDs). In this paper, we report a novel triple-tapered near-field optical fiber(More)
We have developed a novel micro optical diffusion sensor (MODS) based on a laser induced dielectrophoresis (LIDEP) enabling small sample volume, high-speed measurement and on-site sensing of the protein conformation. This paper reports the measurement principle, chip design and the validity of the proposed method. In order to verify the applicability of(More)
A novel nanoscale temperature measurement system using polarized near-field light which enables the high spatial resolution at nanoscale has been developed. In this measurement system, the temperature dependence of the rotation of the polarization plane in near field is detected. However, the signal light variation is extremely weak, therefore, more(More)