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 - 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 - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Suso, Henri-Pierre A1 - Rysstad, Gunnar A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes JF - Physica status solidi (a) N2 - A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests. KW - calorimetric gas sensor;hydrogen peroxide;wireless sensor system Y1 - 2013 U6 - http://dx.doi.org/10.1002/pssa.201200920 SN - 1862-6319 VL - 210 IS - 5 SP - 877 EP - 883 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Hennemann, Jörg A1 - Kohl, Claus-Dieter A1 - Reisert, Steffen A1 - Kirchner, Patrick A1 - Schöning, Michael Josef T1 - Copper oxide nanofibres for detection of hydrogen peroxide vapour at high concentrations JF - physica status solidi (a) N2 - We present a sensor concept based on copper(II)oxide (CuO) nanofibres for the detection of hydrogen peroxide (H2O2) vapour in the percent per volume (% v/v) range. The fibres were produced by using the electrospinning technique. To avoid water condensation in the pores, the fibres were initially modified by an exposure to H2S to get an enclosed surface. By a thermal treatment at 350 °C the fibres were oxidised back to CuO. Thereby, the visible pores disappear which was verified by SEM analysis. The fibres show a decrease of resistance with increasing H2O2 concentration which is due to the fact that hydrogen peroxide is an oxidising gas and CuO a p-type semiconductor. The sensor shows a change of resistance within the minute range to the exposure until the maximum concentration of 6.9% v/v H2O2. At operating temperatures below 450 °C the corresponding sensor response to a concentration of 4.1% v/v increases. The sensor shows a good reproducibility of the signal at different measurements. CuO seems to be a suitable candidate for the detection of H2O2 vapour at high concentrations. Resistance behaviour of the sensor under exposure to H2O2 vapours between 2.3 and 6.9% v/v at an operating temperature of 450 °C. Y1 - 2013 U6 - http://dx.doi.org/10.1002/pssa.201200775 SN - 1862-6319 VL - 210 IS - 5 SP - 859 EP - 863 PB - Wiley CY - Weinheim ER -