@article{SchoeningKirchnerNgetal.2010, author = {Sch{\"o}ning, Michael Josef and Kirchner, Patrick and Ng, Yue Ann and Spelthahn, Heiko and Schneider, Andreas and Henkel, Hartmut and Friedrich, Peter and Kolstad, Jens and Berger, J{\"o}rg and Keusgen, Michael}, title = {Gas sensor investigation based on a catalytically activated thin-film thermopile for H2O2 detection}, series = {Physica Status Solidi (A). 207 (2010), H. 4}, journal = {Physica Status Solidi (A). 207 (2010), H. 4}, isbn = {1862-6300}, pages = {787 -- 792}, year = {2010}, language = {en} } @article{KirchnerLiSpelthahnetal.2009, author = {Kirchner, Patrick and Li, B. and Spelthahn, H. and Henkel, H. and Friedrich, P. and Kolstad, J. and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes}, series = {Procedia Chemistry. 1 (2009), H. 1}, journal = {Procedia Chemistry. 1 (2009), H. 1}, isbn = {1876-6196}, pages = {983 -- 986}, year = {2009}, language = {en} } @article{KirchnerLiSpelthahnetal.2011, author = {Kirchner, Patrick and Li, Bin and Spelthahn, Heiko and Henkel, Hartmut and Schneider, Andreas and Friedrich, Peter and Kolstad, Jens and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes}, series = {Sensors and Actuators B: Chemical. 154 (2011), H. 2}, journal = {Sensors and Actuators B: Chemical. 154 (2011), H. 2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {1873-3077}, pages = {257 -- 263}, year = {2011}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2011, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Berger, J{\"o}rg and Suso, Henri-Pierre and Kupyna, Andriy and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Optimisation and fabrication of a calorimetric gas sensor built up on a polyimide substrate for H2O2 monitoring}, series = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, journal = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, publisher = {Wiley}, address = {Weinheim}, isbn = {1862-6319}, pages = {1235 -- 1240}, year = {2011}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2010, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Rysstad, G. and Berger, J. and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Procedia Engineering. 5 (2010)}, journal = {Procedia Engineering. 5 (2010)}, isbn = {1877-7058}, pages = {264 -- 267}, year = {2010}, language = {en} } @article{KirchnerReisertPuetzetal.2012, author = {Kirchner, Patrick and Reisert, Steffen and P{\"u}tz, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100773}, pages = {859 -- 863}, year = {2012}, abstract = {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.}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2012, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Berger, J{\"o}rg and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef and Keusgen, Michael}, title = {Realisation of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.01.032}, pages = {60 -- 66}, year = {2012}, abstract = {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.}, language = {en} } @incollection{KirchnerReisertSchoening2014, author = {Kirchner, Patrick and Reisert, Steffen and Sch{\"o}ning, Michael Josef}, title = {Calorimetric gas sensors for hydrogen peroxide monitoring in aseptic food processes}, series = {Gas sensing fundamentals. (Springer Series on Chemical Sensors and Biosensors ; 15)}, booktitle = {Gas sensing fundamentals. (Springer Series on Chemical Sensors and Biosensors ; 15)}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-642-54518-4 (Print) ; 978-3-642-54519-1 (Online)}, doi = {10.1007/5346_2013_51}, pages = {279 -- 309}, year = {2014}, abstract = {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.}, language = {en} } @inproceedings{OberlaenderKirchnerKeusgenetal.2014, author = {Oberl{\"a}nder, Jan and Kirchner, Patrick and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Flexible polyimide-based calorimetric gas sensors for monitoring hy-drogen peroxide in sterilisation processes of aseptic filling machines}, series = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, booktitle = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, publisher = {VDE-Verl.}, address = {D{\"u}sseldorf}, organization = {VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, isbn = {978-3-8007-3622-5}, pages = {1 -- 4}, year = {2014}, language = {en} } @article{OberlaenderBrommWendeleretal.2015, author = {Oberl{\"a}nder, Jan and Bromm, Alexander and Wendeler, Luisa and Iken, Heiko and Palomar Duran, Marlena and Greeff, Anton and Kirchner, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards a biosensor to monitor the sterilisation efficiency of aseptic filling machines}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431900}, pages = {1299 -- 1305}, year = {2015}, abstract = {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.}, language = {en} }