TY  - JOUR
A1  - Murib, Mohammed Sharif
A1  - Yeap, Weng-Siang
A1  - Martens, Daan
A1  - Bienstman, Peter
A1  - Ceuninck, Ward de
A1  - Grinsven, Bart van
A1  - Schöning, Michael Josef
A1  - Michiels, Luc
A1  - Haenen, Ken
A1  - Ameloot, Marcel
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Photonic detection and characterization of DNA using sapphire microspheres
JF  - Journal of biomedical optics
N2  - A microcavity-based deoxyribonucleic acid (DNA) optical biosensor is demonstrated for the first time using synthetic sapphire for the optical cavity. Transmitted and elastic scattering intensity at 1510 nm are analyzed from a sapphire microsphere (radius 500  μm, refractive index 1.77) on an optical fiber half coupler. The 0.43 nm angular mode spacing of the resonances correlates well with the optical size of the sapphire sphere. Probe DNA consisting of a 36-mer fragment was covalently immobilized on a sapphire microsphere and hybridized with a 29-mer target DNA. Whispering gallery modes (WGMs) were monitored before the sapphire was functionalized with DNA and after it was functionalized with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The shift in WGMs from the surface modification with DNA was measured and correlated well with the estimated thickness of the add-on DNA layer. It is shown that ssDNA is more uniformly oriented on the sapphire surface than dsDNA. In addition, it is shown that functionalization of the sapphire spherical surface with DNA does not affect the quality factor (Q≈104) of the sapphire microspheres. The use of sapphire is especially interesting because this material is chemically resilient, biocompatible, and widely used for medical implants.
Y1  - 2014
U6  - http://dx.doi.org/10.1117/1.JBO.19.9.097006
SN  - 1560-2281 (E-Journal); 1083-3668 (Print)
VL  - 19
IS  - 9
SP  - 097006
PB  - SPIE
CY  - Bellingham
ER  - 
TY  - CHAP
A1  - Knott, Thomas C.
A1  - Sofronia, Raluca E.
A1  - Gerressen, Marcus
A1  - Law, Yuen
A1  - Davidescu, Arjana
A1  - Savii, George G.
A1  - Gatzweiler, Karl-Heinz
A1  - Staat, Manfred
A1  - Kuhlen, Torsten W.
T1  - Preliminary bone sawing model for a virtual reality-based training simulator of bilateral sagittal split osteotomy
T2  - Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)
N2  - Successful bone sawing requires a high level of skill and experience, which could be gained by the use of Virtual Reality-based simulators. A key aspect of these medical simulators is realistic force feedback. The aim of this paper is to model the bone sawing process in order to develop a valid training simulator for the bilateral sagittal split osteotomy, the most often applied corrective surgery in case of a malposition of the mandible. Bone samples from a human cadaveric mandible were tested using a designed experimental system. Image processing and statistical analysis were used for the selection of four models for the bone sawing process. The results revealed a polynomial dependency between the material removal rate and the applied force. Differences between the three segments of the osteotomy line and between the cortical and cancellous bone were highlighted.
KW  - Bone sawing
KW  - virtual reality
KW  - training simulator
Y1  - 2014
SN  - 978-3-319-12057-7 (Online)
SN  - 978-3-319-12056-0 (Print)
U6  - http://dx.doi.org/10.1007/978-3-319-12057-7_1
SP  - 1
EP  - 10
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Siqueira, Jose R.
A1  - Molinnus, Denise
A1  - Beging, Stefan
A1  - Schöning, Michael Josef
T1  - Incorporating a hybrid urease-carbon nanotubes sensitive nanofilm on capacitive field-effect sensors for urea detection
JF  - Analytical chemistry
N2  - The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor’s surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance–voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.
Y1  - 2014
U6  - http://dx.doi.org/10.1021/ac500458s
SN  - 1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)
VL  - 86
IS  - 11
SP  - 5370
EP  - 5375
PB  - ACS Publications
CY  - Columbus
ER  - 
TY  - CHAP
A1  - Voronkova, Eva B.
A1  - Bauer, Svetlana M.
A1  - Kotliar, Konstantin
T1  - Computer simulation of the cornea-scleral shell as applied to pressure-volume relationship in the human eye
T2  - 2014 International Conference on Computer Technologies in Physical and Engineering Applications :  ICCTPEA 2014 : proceedings : June 30 2014-July 4 2014, St. Petersburg
Y1  - 2014
SN  - 978-1-4799-5315-8
SP  - 204
EP  - 205
ER  - 
TY  - JOUR
A1  - Müller, Martin
A1  - Hirschfeld, Julian
A1  - Lambertz, Rita
A1  - Schulze Lohoff, Andreas
A1  - Lustfeld, Hans
A1  - Pfeifer, Heinz
A1  - Reißel, Martin
T1  - Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks
JF  - Journal of power sources
N2  - In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.jpowsour.2014.08.045
SN  - 1873-2755 (E-Journal); 0378-7753 (Print)
VL  - 272
SP  - 225
EP  - 232
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Guo, Yuanyuan
A1  - Seki, Kosuke
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Device simulation of the light-addressable potentiometric sensor with a novel photoexcitation method for a higher spatial resolution
JF  - Procedia Engineering
N2  - A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) realized a higher spatial resolution of chemical imaging. In this method, a modulated light probe, which generates the alternating photocurrent signal, is surrounded by a ring of constant light, which suppresses the lateral diffusion of photocarriers by enhancing recombination. A device simulation verified that a higher spatial resolution could be obtained by adjusting the gap between the modulated and constant light. It was also found that a higher intensity and a longer wavelength of constant light was more effective. However, there exists a tradeoff between the spatial resolution and the amplitude of the photocurrent, and thus, the signal-to-noise ratio. A tilted incidence of constant light was applied, which could achieve even higher resolution with a smaller loss of photocurrent.
KW  - Light-addressable Potentiometric Sensor
KW  - novel photoexcitation method
KW  - tilted constant illumination
KW  - spatial resolution
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.369
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 456
EP  - 459
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, K.
A1  - Seki, K.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Enhancement of the spatial resolution of the chemical imaging sensor by a hybrid fiber-optic illumination
JF  - Procedia Engineering
N2  - The chemical imaging sensor, which is based on the principle of the light-addressable potentiometric sensor (LAPS), is a powerful tool to visualize the spatial distribution of chemical species on the sensor surface. The spatial resolution of this sensor depends on the diffusion of photocarriers excited by a modulated light. In this study, a novel hybrid fiber-optic illumination was developed to enhance the spatial resolution. It consists of a modulated light probe to generate a photocurrent signal and a ring of constant light, which suppresses the lateral diffusion of minority carriers excited by the modulated light. It is demonstrated that the spatial resolution was improved from 92 μm to 68 μm.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.563
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 612
EP  - 615
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies
JF  - Procedia Engineering
N2  - Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride).
KW  - LAPS
KW  - lable-free detection
KW  - DNA hybridization
KW  - field-effect sensor
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.647
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 755
EP  - 758
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Reisert, Steffen
A1  - Schubert, J.
A1  - Zander, W.
A1  - Begoyan, V. K.
A1  - Buniatyan, V. V.
A1  - Schöning, Michael Josef
T1  - Chemical sensors based on a high-k perovskite oxide of barium strontium titanate
JF  - Procedia Engineering
N2  - High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors for liquids. In this work, BST films have been applied as a sensitive transducer material for a label-free detection of adsorbed charged macromolecules (positively charged polyelectrolytes) and concentration of hydrogen peroxide vapor as well as protection insulator layer for a contactless electrolyte-conductivity sensor. The experimental results of characterization of individual sensors are presented. Special emphasis is devoted towards the development of a capacitively-coupled contactless electrolyte-conductivity sensor.
KW  - barium strontium titanate
KW  - high-k material
KW  - contactless conductivity sensor
KW  - multi-functional material
KW  - hydrogen peroxide
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.258
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 28
EP  - 31
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Krischer, M.
A1  - Wenzel, L.
A1  - Leinhos, Marcel
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor
JF  - Procedia Engineering
N2  - A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers.
KW  - Field-effect sensor
KW  - enzymatic (bio)degradation
KW  - poly(d, l-lactic acid)
KW  - in-situ monitoring
KW  - impedance spectroscopy
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.689
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 1314
EP  - 1317
PB  - Elsevier
CY  - Amsterdam
ER  -