% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Weidlich:838348,
      author       = {Weidlich, Sabrina},
      title        = {{N}anoscale 3{D} structures towards improved cell-chip
                      coupling on microelectrode arrays},
      volume       = {156},
      school       = {RWTH Aachen University},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2017-06973},
      isbn         = {978-3-95806-278-8},
      series       = {Schriften des Forschungszentrums Jülich. Reihe
                      Schlüsseltechnologien / Key Technologies},
      pages        = {II, 154 S.},
      year         = {2017},
      note         = {RWTH Aachen, Diss., 2017},
      abstract     = {The human brain is a highly interconnected system,
                      consisting of about 86 billion neurons,$^{[1]}$ each forming
                      on average 7,000 connections to neighboring cells.$^{[2]}$
                      While neuroscientists have achieved various breakthroughs
                      elucidating the underlying principles of neuronal
                      communication in the past decades, the goal of an in-depth
                      understanding of the complex events involved in network
                      communication and processes such as learning remains
                      unattained. One approach often employed to reduce the
                      complexity and thereby facilitate high-resolution studies of
                      the cellular interactionis the application of microelectrode
                      arrays (MEAs). They enable the $\textit{in vitro}$
                      investigation of small neuronal networks, yielding
                      correlated data of the cellular activity with high temporal
                      resolution. However, MEAs suffer from inherently low signal
                      amplitudes due to a loose cell-chip contact and thus
                      insufficient coupling between the cellular signals and the
                      electrode. In the past decade, three dimensional electrode
                      designs have been extensively studied as possible solution
                      for the problem of low signal amplitudes during MEA-based
                      investigations of electrogenic cells. They improve the
                      cell-chip coupling through the establishment of a tighter
                      interface between biology and electronics. However, while
                      many different 3D designs have been suggested in the
                      literature, the requirements for a direct comparison of the
                      recording capabilities yielded by the different structures
                      have so far not been met. The aim of this body of work
                      therefore is the development of an approach allowing for the
                      parallel fabrication of multiple different 3D designs on a
                      single chip and thus parallel testing on the biological
                      system. In the first part of this thesis, electron-beam
                      lithography is employed in conjunction with electrode
                      position for a parallelized preparation of thousands of 3D
                      structures on gold-on-silicon substrates. In this manner,
                      the common 3D geometries as reported in the literature -
                      pillars, hollow pillars, and mushroom-shaped structures -
                      are produced. Furthermore, hollow mushrooms are developed as
                      novel 3D design. The interaction of the structures with both
                      cardiomyocyte-like HL-1 cells as well as rat cortical
                      neurons is investigated. In the second part of this thesis,
                      the developed 3D structures are transferred onto MEAs. A
                      thorough investigation of the galvanization procedure yields
                      parameters that enable the real-time control of the
                      nanoscale structure size during the electrode position
                      process. In this way, 3D electrodes of different shape and
                      size can be prepared on a single MEA and thus be
                      investigated simultaneously with respect to their
                      interaction with electrogenic cells. Electrophysiological
                      studies are performed employing cardiomyocyte-like HL-1
                      cells as model system. Furthermore, various modifications of
                      the 3D structures are discussed, aiming at improved
                      electrical characteristics for future investigations. In
                      conclusion, this body of work presents a well-controlled
                      process for the preparation of 3D structures on MEAs,
                      thereby facilitating the preparation of multiple different
                      three-dimensional designs on a single chip. This forms the
                      basis for an in-depth characterization of the improvement of
                      the cell-chip coupling yielded by the different 3D designs.},
      cin          = {ICS-8},
      cid          = {I:(DE-Juel1)ICS-8-20110106},
      pnm          = {552 - Engineering Cell Function (POF3-552)},
      pid          = {G:(DE-HGF)POF3-552},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:0001-2017121335},
      url          = {https://juser.fz-juelich.de/record/838348},
}