TY  - JOUR
A1  - Wagner, Torsten
A1  - Werner, Frederik
A1  - Miyamoto, Ko-Ichiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - A high-density multi-point LAPS set-up using a VCSEL array and FPGA control
JF  - Sensors and Actuators B: Chemical. 154 (2011), H. 2
Y1  - 2011
SN  - 1873-3077
N1  - EUROSENSORS XXIII
SP  - 124
EP  - 128
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Hayashi, Kosuke
A1  - Sakamoto, Azuma
A1  - Werner, Frederik
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - A high-Q resonance-mode measurement of EIS capacitive sensor by elimination of series resistance
JF  - Sensor and Actuators B: Chemical
N2  - An EIS capacitive sensor is a semiconductor-based potentiometric sensor, which is sensitive to the ion concentration or pH value of the solution in contact with the sensing surface. To detect a small change in the ion concentration or pH, a small capacitance change must be detected. Recently, a resonance-mode measurement was proposed, in which an inductor was connected to the EIS capacitive sensor and the resonant frequency was correlated with the pH value. In this study, the Q factor of the resonant circuit was enhanced by canceling the internal resistance of the reference electrode and the internal resistance of the inductor coil with the help of a bypass capacitor and a negative impedance converter, respectively. 1% variation of the signal in the developed system corresponded to a pH change of 3.93 mpH, which was about 1/12 of the conventional method, suggesting a better performance in detection of a small pH change.
KW  - Negative impedance convertor
KW  - Resonance-mode measurement
KW  - Chemical sensor
KW  - EIS capacitive sensor
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.snb.2017.03.002
SN  - 0925-4005
VL  - 248
SP  - 1006
EP  - 1010
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Molina, R.
A1  - Biselli, Manfred
A1  - Canzoneri, Michele
A1  - Schnitzler, Thomas
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - A light-addressable potentiometric sensor system for fast, simultaneous and spatial detection of the metabolic activity of biological cells
JF  - Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.)
Y1  - 2007
SN  - 1-4244-0841-5
N1  - Eurosensors 21, 2007, Lyon ; International Conference on Solid-State Sensors, Actuators and Microsystems 14, 2007, Lyon
SP  - 1107
EP  - 1110
PB  - IEEE
CY  - Piscataway
ER  - 
TY  - JOUR
A1  - Miyamato, Ko-ichiro
A1  - Sakakita, Sakura
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Application of chemical imaging sensor to in-situ pH imaging in the vicinity of a corroding metal surface
JF  - Electrochimica Acta
N2  - The chemical imaging sensor was applied to in-situ pH imaging of the solution in the vicinity of a corroding surface of stainless steel under potentiostatic polarization. A test piece of polished stainless steel was placed on the sensing surface leaving a narrow gap filled with artificial seawater and the stainless steel was corroded under polarization. The pH images obtained during polarization showed correspondence between the region of lower pH and the site of corrosion. It was also found that the pH value in the gap became as low as 2 by polarization, which triggered corrosion.
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.electacta.2015.07.184
SN  - 0013-4686
VL  - 183
SP  - 137
EP  - 142
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Moritz, Werner
A1  - Finger, Friedhelm
A1  - Schöning, Michael Josef
ED  - Comini, Elisabetta
T1  - Application of thin-film amorphous silicon to chemical imaging
JF  - Nanostructured materials and hybrid composites for gas sensors and biomedical applications : symposium held April 18-20, 2006, San Francisco , California, U.S.A.
Y1  - 2006
SN  - 9781558998711
N1  - Materials Research Society symposia proceedings; v. 915
IS  - Paper 0910-A-20-01
SP  - 1
EP  - 10
ER  - 
TY  - JOUR
A1  - Miyamoto, K.
A1  - Kuwabara, Yohei
A1  - Kanoh, Shin'ichiro
A1  - Yoshinobu, Tatsuo
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Chemical image scanner based on FDM-LAPS
JF  - Sensors and Actuators B: Chemical. 137 (2009), H. 2
Y1  - 2009
SN  - 0925-4005
SP  - 533
EP  - 538
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Ichimura, Hiroki
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel
JF  - Sensors and actuators. B: Chemical
N2  - The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation.
Y1  - 2013
U6  - http://dx.doi.org/10.1016/j.snb.2013.04.057
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
N1  - Part of special issue "Selected Papers from the 26th European Conference on Solid-State Transducers"
VL  - 189
SP  - 240
EP  - 245
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Mimura, Shuhei
A1  - Kanoh, Shin`ichiro
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Constant-phase-mode operation of the light-addressable potentiometric sensor
JF  - Procedia Chemistry. 1 (2009), H. 1
Y1  - 2009
SN  - 1876-6196
N1  - Proceedings of the Eurosensors XXIII conference ; Eurosensors 23
SP  - 1487
EP  - 1490
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Mimura, Shuhei
A1  - Kanoh, Shiníchiro
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Constant-phase-mode operation of the light-addressable potentiometric sensor
JF  - Sensors and Actuators B: Chemical. 154 (2011), H. 2
Y1  - 2011
SN  - 1873-3077
N1  - EUROSENSORS XXIII
SP  - 119
EP  - 123
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Krumbe, Christoph
A1  - Schumacher, Katharina
A1  - Groebel, Simone
A1  - Spelthahn, Heiko
A1  - Stellberg, Michael
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli by a light-addressable potentiometric sensor
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1340
EP  - 1344
PB  - Wiley
CY  - Weinheim
ER  -