Book/Dissertation / PhD Thesis FZJ-2017-06973

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Nanoscale 3D structures towards improved cell-chip coupling on microelectrode arrays



2017
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-278-8

Jülich : Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag, Schriften des Forschungszentrums Jülich. Reihe Schlüsseltechnologien / Key Technologies 156, II, 154 S. () = RWTH Aachen, Diss., 2017

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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.


Note: RWTH Aachen, Diss., 2017

Contributing Institute(s):
  1. Bioelektronik (ICS-8)
Research Program(s):
  1. 552 - Engineering Cell Function (POF3-552) (POF3-552)

Appears in the scientific report 2017
Database coverage:
Creative Commons Attribution CC BY 4.0 ; OpenAccess
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The record appears in these collections:
Institute Collections > IBI > IBI-3
Document types > Theses > Ph.D. Theses
Document types > Books > Books
Workflow collections > Public records
ICS > ICS-8
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Open Access

 Record created 2017-10-12, last modified 2022-09-30