TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Itabashi, Akinori
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - High-speed chemical imaging inside a microfluidic channel
JF  - Sensors and actuators. B: Chemical
N2  - In this study, a high-speed chemical imaging system was developed for visualization of the interior of a microfluidic channel. A microfluidic channel was constructed on the sensor surface of the light-addressable potentiometric sensor (LAPS), on which the ion concentrations could be measured in parallel at up to 64 points illuminated by optical fibers. The temporal change of pH distribution inside the microfluidic channel was recorded at a maximum rate of 100 frames per second (fps). The high frame rate allowed visualization of moving interfaces and plugs in the channel even at a flow velocity of 111 mm/s, which suggests the feasibility of plug-based microfluidic devices for flow-injection analysis (FIA).
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.snb.2013.12.090
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
VL  - 194
SP  - 521
EP  - 527
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Itabashi, Akinori
A1  - Kosaka, Naoki
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - High-speed chemical imaging system based on front-side-illuminated LAPS
JF  - Sensors and actuators B: Chemical
N2  - The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the spatial distribution of specific ions on the sensing surface. The conventional chemical imaging system based on the light-addressable potentiometric sensor (LAPS), however, required a long time to obtain a chemical image, due to the slow mechanical scan of a single light beam. For high-speed imaging, a plurality of light beams modulated at different frequencies can be employed to measure the ion concentrations simultaneously at different locations on the sensor plate by frequency division multiplex (FDM). However, the conventional measurement geometry of back-side illumination limited the bandwidth of the modulation frequency required for FDM measurement, because of the low-pass filtering characteristics of carrier diffusion in the Si substrate. In this study, a high-speed chemical imaging system based on front-side-illuminated LAPS was developed, which achieved high-speed spatiotemporal recording of pH change at a rate of 70 frames per second.
Y1  - 2013
U6  - http://dx.doi.org/10.1016/j.snb.2013.03.016
SN  - 1873-3077
VL  - 182
SP  - 315
EP  - 321
PB  - Elsevier
CY  - Amsterdam
ER  -