@article{NickJoshiSchneideretal.2012, author = {Nick, Christoph and Joshi, Ravi and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {Three-Dimensional Carbon Nanotube Electrodes for Extracellular Recording of Cardiac Myocytes}, series = {Biointerphases, 2012}, volume = {7}, journal = {Biointerphases, 2012}, publisher = {Springer-Verl.}, doi = {10.1007/s13758-012-0058-2}, pages = {58}, year = {2012}, abstract = {Three-Dimensional Carbon Nanotube Electrodes for Extracellular Recording of Cardiac Myocytes}, subject = {Kohlenstoff-Nanor{\"o}hre}, language = {en} } @phdthesis{Nick2015, author = {Nick, Christoph}, title = {Mikrointegrierte Nanostrukturen mit hohem Aspektverh{\"a}ltnis als neuronale Schnittstelle}, school = {Technische Hochschule Aschaffenburg}, year = {2015}, subject = {Neuronales Netz}, language = {de} } @article{NickYadavJoshietal.2015, author = {Nick, Christoph and Yadav, Sandeep and Joshi, Ravi and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {A three-dimensional microelectrode array composed of vertically aligned ultra-dense carbon nanotube networks}, series = {Applied Physics Letters}, volume = {2015}, journal = {Applied Physics Letters}, number = {107}, doi = {10.1063/1.4926330}, pages = {1 -- 1}, year = {2015}, abstract = {Electrodes based on carbon nanotubes are a promising approach to manufacture highly sensitive sensors with a low limit of signal detection and a high signal-to-noise ratio. This is achieved by dramatically increasing the electrochemical active surface area without increasing the overall geometrical dimensions. Typically, carbon nanotube electrodes are nearly planar and composed of randomly distributed carbon nanotube networks having a limited surface gain for a specific geometrical surface area. To overcome this limitation, we have introduced vertically aligned carbon nanotube (VACNT) networks as electrodes, which are arranged in a microelectrode pattern of 60 single electrodes. Each microelectrode features a very high aspect ratio of more than 300 and thus a dramatically increased surface area. These microelectrodes composed of VACNT networks display dramatically decreased impedance over the entire frequency range compared to planar microelectrodes caused by the enormous capacity increase. This is experimentally verified by electrochemical impedance spectroscopy and cyclic voltammetry.}, subject = {Mikroelektrode}, language = {en} } @article{NickDausBesteletal.2013, author = {Nick, Christoph and Daus, Andreas and Bestel, Robert and Goldhammer, Michael and Steger, Frederik and Thielemann, Christiane}, title = {DrCell - a software tool for the analysis of cell signals recorded with extracellular microelectrodes}, series = {Signal processing: an international journal (SPIJ)}, volume = {7}, journal = {Signal processing: an international journal (SPIJ)}, number = {2}, pages = {96 -- 109}, year = {2013}, subject = {Mikroelektrode}, language = {de} } @inproceedings{NickHockEmmerichetal.2015, author = {Nick, Christoph and Hock, Christina and Emmerich, Florian and Belle, Stefan and Thielemann, Christiane and Asmus, Tim and Loose, Thomas and Wienand, Karlheinz}, title = {Ultrathin gold as sensor platform for biomolecules}, series = {2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China}, booktitle = {2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China}, doi = {10.1109/3M-NANO.2015.7425462}, year = {2015}, abstract = {Due to the increasing number of diabetes patients worldwide there is an enormous need for accurate, fast and someday also continuous or even closed loop monitoring of blood glucose level. More than 50 years after Clark and Lyons proposed the first glucose enzyme electrodes this concept is still widely in use today. Most concepts use the enzyme glucose oxidase (GOx) that reacts with glucose. These reactions cause a current that is proportional to the amount of glucose present at the sensor. Thus, if the sample volume is known, the blood sugar level can be measured. Although these electrodes have been in use for so long they have the disadvantage of a limited shelf time. In this work we present an enzyme free approach for glucose detection applying ultrathin gold films. According to the basic Fuchs-Sondheimer-theory and other more sophisticated models the resistivity of ultrathin metal films is dominated by scattering effects at their surface. Chemical reactions at the metallic surface are expected to change the conductivity properties and thus these changes can be used to detect molecules. This can be done by creating a self-assembled monolayer at the gold surface. When molecules such as glucose bind to the end groups of this layer the electron scattering and thus the conductivity of the film is expected to change. Ultrathin gold films with a thickness of 6 nm show the largest relative change in resistivity and are thus the preferred film thickness for this application. These gold films show a significant change in resistance when model molecules sodium sulfide and dextran are present, whereas the resistance of a platinum reference electrode does not change significantly.}, subject = {Biosensor}, language = {en} } @inproceedings{NickThielemannJoshietal.2011, author = {Nick, Christoph and Thielemann, Christiane and Joshi, Ravi and Schneider, J{\"o}rg}, title = {Niedrigtemperatur-Transfer von vertikal ausgerichteten Kohlenstoff Nanor{\"o}hren auf Mikrostrukturen}, series = {Mikro-Nano-Integration - 3. GMM-Workshop, Stuttgart, Deutschland, 2011}, booktitle = {Mikro-Nano-Integration - 3. GMM-Workshop, Stuttgart, Deutschland, 2011}, pages = {5}, year = {2011}, abstract = {Vertikal angeordnete Kohlenstoff Nanor{\"o}hren (engl. vertically aligned carbon nanotubes; VA-CNT) k{\"o}nnen seit einigen Jahren mit hoher Reproduzierbarkeit durch CVD-Verfahren bei 600 °C - 800 °C auf Katalysatorschichten aus Aluminium und Eisen hergestellt werden. Sie zeigen sehr gute Eigenschaften im Bereich der Feldemission, aber auch in sub-µm Vias. Allerdings sind die relativ hohen Temperaturen oft nicht prozesskompatibel und m{\"u}ssen vermieden werden um keine Degradation darunterliegender Strukturen in Kauf zu nehmen. Da die Reduzierung der CVD-Temperaturen beim Wachstum der VA-CNTs unter 600 °C zu hohen Defektraten f{\"u}hrt, schlagen wir ein neues Verfahren zum Transfer der VA-CNTs bei niedrigen Temperaturen vor. In einer Kombination aus Flip-Chip- und Stempel-Technik werden hoch geordnete, mikrostrukturierte VA-CNTs auf temperaturempfindliche Substrate aus Kalk-Natron-Glas, Gold oder Kupfer bei Temperaturen von 100 °C transferiert. Die vertikale Struktur der Nanor{\"o}hren bleibt dabei erhalten. Eine leitende Verbindung kann durch ein leitf{\"a}higes, bio-kompatibles Polymer gew{\"a}hrleistet werden, was eine Erweiterung des Einsatzbereichs auf Life-Science Applikationen erlauben w{\"u}rde.}, subject = {Kohlenstoff-Nanor{\"o}hre}, language = {de} } @inproceedings{YilmazogluAlDaffaieHartnageletal.2012, author = {Yilmazoglu, Oktay and Al-Daffaie, Shihab and Hartnagel, Hans and Joshi, Ravi and Yadav, Sandeep and Schneider, J{\"o}rg and Nick, Christoph and Thielemann, Christiane}, title = {CNT photocathodes based on GaAs high-frequency photoswitches}, series = {25th International Vacuum Nanoelectronics Conference, 9 - 13 July 2012, Jeju, South Korea}, booktitle = {25th International Vacuum Nanoelectronics Conference, 9 - 13 July 2012, Jeju, South Korea}, doi = {10.1109/IVNC.2012.6316840}, year = {2012}, abstract = {A high-frequency photocathode based on carbon nanotube (CNT) blocks on semiisolating GaAs or low-temperature grown GaAs was fabricated and used for electron emission in a diode configuration. The CNT blocks can achieve high currents and current densities of I=0.5 mA and J=28 mA/cm 2 at E=2.1 V/μm, respectively. The photomodulation was achieved with a GaAs photoswitch electrically connected to the bottom of the CNT block emitter. This photocathode can find applications in high frequency tubes and optically driven X-ray sources.}, subject = {Kohlenstoff-Nanor{\"o}hre}, language = {en} } @article{NickSchlaakThielemann2015, author = {Nick, Christoph and Schlaak, Helmut and Thielemann, Christiane}, title = {Simulation and Measurement of Neuroelectrodes' Characteristics with Integrated High Aspect Ratio Nano Structures}, series = {AIMS Journal}, volume = {2015}, journal = {AIMS Journal}, number = {2}, doi = {10.3934/matersci.2015.3.189}, pages = {189 -- 202}, year = {2015}, abstract = {Improving the interface between electrodes and neurons has been the focus of research for the last decade. Neuroelectrodes should show small geometrical surface area and low impedance for measuring and high charge injection capacities for stimulation. Increasing the electrochemically active surface area by using nanoporous electrode material or by integrating nanostructures onto planar electrodes is a common approach to improve this interface. In this paper a simulation approach for neuro electrodes' characteristics with integrated high aspect ratio nano structures based on a point-contact-model is presented. The results are compared with experimental findings conducted with real nanostructured microelectrodes. In particular, effects of carbon nanotubes and gold nanowires integrated onto microelectrodes are described. Simulated and measured impedance properties are presented and its effects onto the transfer function between the neural membrane potential and the amplifier output signal are studied based on the point-contact-model. Simulations show, in good agreement with experimental results, that electrode impedances can be dramatically reduced by the integration of high aspect ratio nanostructures such as gold nanowires and carbon nanotubes. This lowers thermal noise and improves the signal-to-noise ratio for measuring electrodes. It also may increase the adhesion of cells to the substrate and thus increase measurable signal amplitudes.}, subject = {Neuronales Netz}, language = {en} } @article{CibaBestelNicketal.2020, author = {Ciba, Manuel and Bestel, Robert and Nick, Christoph and Ferraz de Arruda, Guilherme and Peron, Thomas and Henrique, Comin C{\´e}sar and da Fontoura Costa, Luciano and Aparecido Rodrigues, Francisco and Thielemann, Christiane}, title = {Comparison of Different Spike Train Synchrony Measures Regarding Their Robustness to Erroneous Data from Bicuculline-Induced Epileptiform Activity}, series = {Neural Computation}, volume = {32}, journal = {Neural Computation}, number = {3}, doi = {10.1162/neco_a_01277}, pages = {1 -- 25}, year = {2020}, abstract = {As synchronized activity is associated with basic brain functions and pathological states, spike train synchrony has become an important measure to analyze experimental neuronal data. Many measures of spike train synchrony have been proposed, but there is no gold standard allowing for comparison of results from different experiments. This work aims to provide guidance on which synchrony measure is best suited to quantify the effect of epileptiform-inducing substances (e.g., bicuculline, BIC) in in vitro neuronal spike train data. Spike train data from recordings are likely to suffer from erroneous spike detection, such as missed spikes (false negative) or noise (false positive). Therefore, different timescale-dependent (cross-correlation, mutual information, spike time tiling coefficient) and timescale-independent (Spike-contrast, phase synchronization (PS), A-SPIKE-synchronization, A-ISI-distance, ARI-SPIKE-distance) synchrony measures were compared in terms of their robustness to erroneous spike trains. For this purpose, erroneous spike trains were generated by randomly adding (false positive) or deleting (false negative) spikes (in silico manipulated data) from experimental data. In addition, experimental data were analyzed using different spike detection threshold factors in order to confirm the robustness of the synchrony measures. All experimental data were recorded from cortical neuronal networks on microelectrode array chips, which show epileptiform activity induced by the substance BIC. As a result of the in silico manipulated data, Spike-contrast was the only measure that was robust to false-negative as well as false-positive spikes. Analyzing the experimental data set revealed that all measures were able to capture the effect of BIC in a statistically significant way, with Spike-contrast showing the highest statistical significance even at low spike detection thresholds. In summary, we suggest using Spike contrast to complement established synchrony measures because it is timescale independent and robust to erroneous spike trains.}, subject = {Neuronales Netz}, language = {en} } @article{NickQuednauSarwaretal.2013, author = {Nick, Christoph and Quednau, Sebastian and Sarwar, Reza and Schlaak, Helmut and Thielemann, Christiane}, title = {High Aspect Ratio Gold Nanopillars on Microelectrodes for Neural Interfaces}, series = {Microsystem Technologies Media}, journal = {Microsystem Technologies Media}, number = {20/10-11}, issn = {0946-7076}, pages = {1849 -- 1857}, year = {2013}, subject = {Neuronales Netz}, language = {en} } @inproceedings{NickBestelStegeretal.2013, author = {Nick, Christoph and Bestel, Robert and Steger, Frederik and Thielemann, Christiane}, title = {Spike Detection, Sorting and Propagation of Cell Signals Recorded with Extracellular Microelectrodes, Engineering in Medicine and Biology Society}, series = {IEMBS'13, 35th Annual International Conference of the IEEE}, booktitle = {IEMBS'13, 35th Annual International Conference of the IEEE}, year = {2013}, subject = {Pulsverarbeitendes neuronales Netz}, language = {en} } @article{NickJoshiSchneideretal.2012, author = {Nick, Christoph and Joshi, Ravi and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {Low Temperature Substrate Transfer Technique for 3D Vertically Aligned Carbon Nanotube Architectures}, series = {International Journal of Surface Science and Engineering}, volume = {6}, journal = {International Journal of Surface Science and Engineering}, number = {3}, doi = {10.1504/IJSURFSE.2012.049057}, pages = {246 -- 246}, year = {2012}, subject = {Kohlenstoff-Nanor{\"o}hre}, language = {en} } @inproceedings{NickJoshiSchlaaketal.2011, author = {Nick, Christoph and Joshi, Ravi and Schlaak, Helmut and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {Multi electrode array with carbon nanotube electrodes for the extra-cellular detection of action potentials}, series = {MikroSystemTechnik Kongress 2011, Darmstadt}, booktitle = {MikroSystemTechnik Kongress 2011, Darmstadt}, year = {2011}, subject = {Mehrfachelektrode}, language = {en} } @inproceedings{NickQuednauSarwaretal.2013, author = {Nick, Christoph and Quednau, Sebastian and Sarwar, Reza and Thielemann, Christiane and Schlaak, Helmut}, title = {Fabrication of high aspect ratio gold nanopillars on microelectrodes for the interface with electrogenic cells}, series = {HARMNST - 10th international workshop on high aspect ratio micro and nano system technologies, Berlin}, booktitle = {HARMNST - 10th international workshop on high aspect ratio micro and nano system technologies, Berlin}, pages = {212 -- 213}, year = {2013}, subject = {Mikroelektrode}, language = {de} } @article{NickYadavJoshietal.2014, author = {Nick, Christoph and Yadav, Sandeep and Joshi, Ravi and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {Growth of Cortical Neurons Grown on Randomly Oriented and Vertically Aligned Dense Carbon Nanotube Networks}, series = {Beilstein Journal of Nanotechnology}, volume = {5}, journal = {Beilstein Journal of Nanotechnology}, pages = {1575 -- 1579}, year = {2014}, subject = {Nervenzelle}, language = {en} } @inproceedings{KoerbitzerKraussNicketal.2015, author = {K{\"o}rbitzer, Berit Silke and Krauß, Peter and Nick, Christoph and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {Graphene electrodes for recording and stimulation of neural cells}, series = {ICREA Workshop on Graphene Nanobiosensors}, booktitle = {ICREA Workshop on Graphene Nanobiosensors}, address = {Barcelona, Spanien}, year = {2015}, subject = {Nervenzelle}, language = {en} } @inproceedings{NickLippertQuednauetal.2014, author = {Nick, Christoph and Lippert, Paul and Quednau, Sebastian and Schlaak, Helmut and Thielemann, Christiane}, title = {Gold Nanopillar Microelectrodes on Low Temperature Curing Polyimide for the Interface with Electrogenic Cells}, series = {Middle East Conference on Biomedical Engineering}, volume = {2014}, booktitle = {Middle East Conference on Biomedical Engineering}, address = {Doha, Qatar}, isbn = {978-1-4799-4799-7}, pages = {55 -- 58}, year = {2014}, subject = {Mikroelektrode}, language = {en} } @inproceedings{NickQuednauSarwaretal.2013, author = {Nick, Christoph and Quednau, Sebastian and Sarwar, Reza and Thielemann, Christiane and Schlaak, Helmut}, title = {Gold-Nanodr{\"a}hte auf Mikroelektroden zur extrazellul{\"a}ren Ableitung elektrogener Zellen}, series = {Mikrosystemtechnik Kongress}, booktitle = {Mikrosystemtechnik Kongress}, publisher = {VDE Verlag}, address = {Aachen, Deutschland}, year = {2013}, subject = {Mikroelektrode}, language = {de} } @inproceedings{SternNickThielemann2014, author = {Stern, Maike and Nick, Christoph and Thielemann, Christiane}, title = {A Novel LabVIEW based Multi-Channel Closed-Loop Stimulator}, series = {9th International Meeting on Substrate-Integrated Micro-electrode Arrays}, volume = {2014}, booktitle = {9th International Meeting on Substrate-Integrated Micro-electrode Arrays}, address = {Reutlingen, Germany}, year = {2014}, subject = {LabVIEW}, language = {en} } @inproceedings{NickSchlaakThielemann2014, author = {Nick, Christoph and Schlaak, Helmut and Thielemann, Christiane}, title = {PEDOT:PSS coated Gold Nanopillar Micro-electrodes for Neural Interfaces}, series = {4th International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale}, volume = {2014}, booktitle = {4th International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale}, address = {Taipeh, Taiwan}, year = {2014}, subject = {Mikroelektrode}, language = {en} } @article{NickThielemann2014, author = {Nick, Christoph and Thielemann, Christiane}, title = {Are Carbon Nanotube Microelectrodes Manufactured from Dispersion Stable Enough for Neural Interfaces?}, series = {BioNanoScience}, volume = {2014}, journal = {BioNanoScience}, number = {4 / 3}, pages = {216 -- 225}, year = {2014}, subject = {Mikroelektrode}, language = {en} } @inproceedings{NickHeinleinSchneideretal.2012, author = {Nick, Christoph and Heinlein, Thorsten and Schneider, J{\"o}rg and Thielemann, Christiane}, title = {3D Carbon Nanotube Electrodes for Sensing of Neural Activity}, series = {Elsevier World Congress on Biosensors}, booktitle = {Elsevier World Congress on Biosensors}, address = {Cancun, Mexiko}, year = {2012}, subject = {Kohlenstoff-Nanor{\"o}hre}, language = {en} }