@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} } @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{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} }