TY - JOUR A1 - Schöning, Michael Josef A1 - Kirchner, Patrick A1 - Ng, Yue Ann A1 - Spelthahn, Heiko A1 - Schneider, Andreas A1 - Henkel, Hartmut A1 - Friedrich, Peter A1 - Kolstad, Jens A1 - Berger, Jörg A1 - Keusgen, Michael T1 - Gas sensor investigation based on a catalytically activated thin-film thermopile for H2O2 detection JF - Physica Status Solidi (A). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 787 EP - 792 ER - TY - JOUR A1 - Kirchner, Patrick A1 - Li, B. A1 - Spelthahn, H. A1 - Henkel, H. A1 - Friedrich, P. A1 - Kolstad, J. A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes JF - Procedia Chemistry. 1 (2009), H. 1 Y1 - 2009 SN - 1876-6196 N1 - Proceedings of the Eurosensors XXIII conference ; Eurosensors 23 SP - 983 EP - 986 ER - TY - JOUR A1 - Kirchner, Patrick A1 - Li, Bin A1 - Spelthahn, Heiko A1 - Henkel, Hartmut A1 - Schneider, Andreas A1 - Friedrich, Peter A1 - Kolstad, Jens A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes JF - Sensors and Actuators B: Chemical. 154 (2011), H. 2 Y1 - 2011 SN - 1873-3077 N1 - EUROSENSORS XXIII SP - 257 EP - 263 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Friedrich, Peter A1 - Berger, Jörg A1 - Suso, Henri-Pierre A1 - Kupyna, Andriy A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Optimisation and fabrication of a calorimetric gas sensor built up on a polyimide substrate for H2O2 monitoring JF - Physica status solidi (a) : applications and material science. 208 (2011), H. 6 Y1 - 2011 SN - 1862-6319 SP - 1235 EP - 1240 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Friedrich, Peter A1 - Rysstad, G. A1 - Berger, J. A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry JF - Procedia Engineering. 5 (2010) Y1 - 2010 SN - 1877-7058 N1 - Eurosensor XXIV Conference SP - 264 EP - 267 ER - TY - JOUR A1 - Kirchner, Patrick A1 - Reisert, Steffen A1 - Pütz, Patrick A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors JF - Physica Status Solidi (a) N2 - Calorimetric gas sensors for monitoring the H₂O₂ concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set-up of a catalytically active and passive temperature-sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy-based SU-8 photoresist as temperature-stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H₂O₂, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin-coating on the temperature-sensitive structure, wherein spin-coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU-8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H₂O₂ during the characterisation in H₂O₂ atmosphere that demonstrates their suitability as passivation layer for calorimetric H₂O₂ gas sensors. Y1 - 2012 U6 - http://dx.doi.org/10.1002/pssa.201100773 SN - 1862-6319 VL - 209 IS - 5 SP - 859 EP - 863 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Friedrich, Peter A1 - Berger, Jörg A1 - Rysstad, Gunnar A1 - Schöning, Michael Josef A1 - Keusgen, Michael T1 - Realisation of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry JF - Sensors and Actuators B: Chemical N2 - A calorimetric gas sensor is presented for the monitoring of vapour-phase H2O2 at elevated temperature during sterilisation processes in aseptic food industry. The sensor was built up on a flexible polyimide foil (thickness: 25 μm) that has been chosen due to its thermal stability and low thermal conductivity. The sensor set-up consists of two temperature-sensitive platinum thin-film resistances passivated by a layer of SU-8 photo resist and catalytically activated by manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilises the elevated temperature of the evaporated H2O2 aerosol. In an experimental test rig, the sensor has shown a sensitivity of 4.78 °C/(%, v/v) in a H2O2 concentration range of 0%, v/v to 8%, v/v. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied medium temperatures between 210 °C and 270 °C of the gas stream. At flow rates of the gas stream from 8 m3/h to 12 m3/h, the sensor has shown only a slightly reduced sensitivity at a low flow rate of 8 m3/h. The sensor characterisation demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of industrial sterilisation processes. KW - Sterilisation process KW - Hydrogen peroxide KW - Polyimide KW - Calorimetric gas sensor Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2011.01.032 SN - 0925-4005 N1 - Part of special issue "Eurosensors XXIV, 2010" VL - 170 SP - 60 EP - 66 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Kirchner, Patrick A1 - Reisert, Steffen A1 - Schöning, Michael Josef T1 - Calorimetric gas sensors for hydrogen peroxide monitoring in aseptic food processes T2 - Gas sensing fundamentals. (Springer Series on Chemical Sensors and Biosensors ; 15) N2 - For the sterilisation of aseptic food packages it is taken advantage of the microbicidal properties of hydrogen peroxide (H2O2). Especially, when applied in vapour phase, it has shown high potential of microbial inactivation. In addition, it offers a high environmental compatibility compared to other chemical sterilisation agents, as it decomposes into oxygen and water, respectively. Due to a lack in sensory detection possibilities, a continuous monitoring of the H2O2 concentration was recently not available. Instead, the sterilisation efficacy is validated using microbiological tests. However, progresses in the development of calorimetric gas sensors during the last 7 years have made it possible to monitor the H2O2 concentration during operation. This chapter deals with the fundamentals of calorimetric gas sensing with special focus on the detection of gaseous hydrogen peroxide. A sensor principle based on a calorimetric differential set-up is described. Special emphasis is given to the sensor design with respect to the operational requirements under field conditions. The state-of-the-art regarding a sensor set-up for the on-line monitoring and secondly, a miniaturised sensor for in-line monitoring are summarised. Furthermore, alternative detection methods and a novel multi-sensor system for the characterisation of aseptic sterilisation processes are described. KW - Calorimetric gas sensor KW - Hydrogen peroxide KW - Multi-sensor system Y1 - 2014 SN - 978-3-642-54518-4 (Print) ; 978-3-642-54519-1 (Online) U6 - http://dx.doi.org/10.1007/5346_2013_51 SP - 279 EP - 309 PB - Springer CY - Heidelberg 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 - Oberländer, Jan A1 - Bromm, Alexander A1 - Wendeler, Luisa A1 - Iken, Heiko A1 - Palomar Duran, Marlena A1 - Greeff, Anton A1 - Kirchner, Patrick A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards a biosensor to monitor the sterilisation efficiency of aseptic filling machines JF - Physica status solidi (a) N2 - Sterilisation processes are compulsory in medicine, pharmacy, and food industries to prevent infections of consumers and microbiological contaminations of products. Monitoring the sterilisation by conventional microbiological methods is time- and lab-consuming. To overcome this problem, in this work a novel biosensor has been proposed. The sensor enables a fast method to evaluate sterilisation processes. By means of thin-film technology the sensor's transducer structures in form of IDEs (interdigitated electrodes) have been fabricated on a silicon substrate. Physical characterisation of the developed sensor was done by AFM, SEM, and profilometry. Impedance analyses were conducted for the electrical characterisation. As microbiological layer spores of B. atrophaeus have been immobilised on the sensing structure; spores of this type are a well-known sterilisation test organism. Impedance measurements at a fixed frequency over time were performed to monitor the immobilisation process. A sterilisation process according to aseptic filling machines was applied to demonstrate the sensor functionality. After both, immobilisation and sterilisation, a change in impedance could successfully be detected. Y1 - 2015 U6 - http://dx.doi.org/10.1002/pssa.201431900 SN - 1862-6319 VL - 212 IS - 6 SP - 1299 EP - 1305 PB - Wiley CY - Weinheim ER -