TY - JOUR A1 - Werner, Frederik A1 - Wagner, Torsten A1 - Yoshinobu, Tatsuo A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Frequency behaviour of light-addressable potentiometric sensors JF - Physica Status Solidi (A) N2 - Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed. Y1 - 2013 U6 - http://dx.doi.org/10.1002/pssa.201200929 SN - 1521-396X ; 0031-8965 VL - 210 IS - 5 SP - 884 EP - 891 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Wagner, Torsten A1 - Werner, Frederik A1 - Miyamoto, Ko-ichiro A1 - Ackermann, Hans-Josef A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef T1 - FPGA-based LAPS device for the flexible design of sensing sites on functional interfaces JF - Physica Status Solidi (A). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 844 EP - 849 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef T1 - Flow-velocity microsensors based on semiconductor field-effect structures JF - Sensors. 3 (2003), H. 7 Y1 - 2003 SN - 1424-8220 SP - 202 EP - 212 ER - TY - JOUR A1 - Wang, J. A1 - Krause, R. A1 - Block, K. A1 - Musameh, M. A1 - Mulchandani, A. A1 - Schöning, Michael Josef T1 - Flow injection amperometric detection of OP nerve agents based on organophosphorus-hydrolase biosensor detector JF - Biosensors & Bioelectronics. 18 (2003), H. 2-3 Y1 - 2003 SN - 0956-5663 SP - 255 EP - 260 ER - TY - CHAP A1 - Oberländer, Jan A1 - Kirchner, Patrick A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Flexible polyimide-based calorimetric gas sensors for monitoring hy-drogen peroxide in sterilisation processes of aseptic filling machines T2 - Sensoren und Messsysteme 2014 ; Beiträge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in Nürnberg. (ITG-Fachbericht ; 250) Y1 - 2014 SN - 978-3-8007-3622-5 SP - 1 EP - 4 PB - VDE-Verl. CY - Düsseldorf ER - TY - JOUR A1 - Wagner, Torsten A1 - Miyamoto, K. A1 - Werner, Frederik A1 - Schöning, Michael Josef A1 - Yoshinobu, T. T1 - Flexible electrochemical imaging with “zoom-in” functionality by using a new type of light-addressable potentiometric sensor Y1 - 2011 N1 - 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS) , Date: 5-9 June 2011 SP - 2133 EP - 2135 PB - IEEE CY - New York ER - TY - JOUR A1 - Vahidpour, Farnoosh A1 - Oberländer, Jan A1 - Schöning, Michael Josef T1 - Flexible Calorimetric Gas Sensors for Detection of a Broad Concentration Range of Gaseous Hydrogen Peroxide: A Step Forward to Online Monitoring of Food-Package Sterilization Processes JF - Phys. Status Solidi A N2 - In this study, flexible calorimetric gas sensors are developed for specificdetection of gaseous hydrogen peroxide (H₂O₂) over a wide concentrationrange, which is used in sterilization processes for aseptic packaging industry.The flexibility of these sensors is an advantage for identifying the chemical components of the sterilant on the corners of the food boxes, so-called “coldspots”, as critical locations in aseptic packaging, which are of great importance. These sensors are fabricated on flexible polyimide films by means of thin-film technique. Thin layers of titanium and platinum have been deposited on polyimide to define the conductive structures of the sensors. To detect the high-temperature evaporated H₂O₂, a differential temperature set-up is proposed. The sensors are evaluated in a laboratory-scaled sterilizationsystem to simulate the sterilization process. The concentration range of the evaporated H₂O₂ from 0 to 7.7% v/v was defined and the sensors have successfully detected high as well as low H₂O₂ concentrations with a sensitivity of 5.04 °C/% v/v. The characterizations of the sensors confirm their precise fabrication, high sensitivity and the novelty of low H₂O₂ concentration detections for future inline monitoring of food-package sterilization. Y1 - 2018 U6 - http://dx.doi.org/10.1002/pssa.201800044 VL - 215 IS - 15 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Werner, Frederik A1 - Schusser, Sebastian A1 - Spalthahn, Heiko A1 - Wagner, Torsten A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef T1 - Field-programmable gate array based controller for multi spot light-addressable potentiometric sensors with integrated signal correction mode JF - Electrochimica Acta N2 - A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.electacta.2011.03.012 SN - 0013-4686 VL - 56 IS - 26 SP - 9656 EP - 9660 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Amberger, F. A1 - Mayer, D. A1 - Han, Y. A1 - Ingebrandt, S. A1 - Offenhäusser, A. A1 - Schöning, Michael Josef T1 - Field-effect sensors with charged macromolecules: Characterisation by capacitance–voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods JF - Biosensors and Bioelectronics. 22 (2007), H. 9-10 Y1 - 2007 SN - 0956-5663 N1 - Selected Papers from the Ninth World Congress On Biosensors. Toronto, Canada 10 - 12 May 2006, Alice X. J . Tang SP - 2100 EP - 2107 ER - TY - CHAP A1 - Poghossian, Arshak A1 - Ingebrandt, S. A1 - Platen, J. A1 - Schöning, Michael Josef T1 - Field-effect sensors with charged macromolecules – from micro towards nano aspects T2 - Biochemical Sensing Utilisation of Micro-and Nanotechnologies, Warschau, Nov. 2005 : Lecture Notes of the ICB Seminar / ed.: M. Mascini, W. Torbicz Y1 - 2006 SP - 74 EP - 81 PB - Polish Academy Sciences Press CY - Warsaw ER -