Book/Dissertation / PhD Thesis

FZJ-2017-03703

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Graphene Devices for Extracellular Measurements

Kireev, D. (Corresponding author)FZJ*

2017
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-265-8

Please use a persistent id in citations: http://hdl.handle.net/2128/15922  urn:nbn:de:0001-2017121302

Abstract: Recording extracellular potentials from electrogenic cells (especially neurons) is the hallmark destination of modern bioelectronics. Graphene is a promising material, which possesses features relevant to bioelectronics applications. Graphene-based electrode arrays (GMEAs) and more complicated graphene field effect transistors (GFETs) comprise a new type of bioelectronic device application. Biocompatibility, stability, excellent and unique electronic properties, scalability, and pure two-dimensional structure make graphene the perfect material for bioelectronic applications. The advantages of graphene as part of such devices are numerous: from a general exibility and biocompatibility to the unique electronic properties of graphene. In this work, the GMEAs and GFETs are fabricated using CVD-grown graphene and a scalable cleanroom-based technology. The devices are fabricated on both rigid and exible substrates. In order to ensure a wafer-scale fabrication of the devices, a new high throughput graphene transfer technique is established. The technique allows me to use just 4 cm$^{2}$ of CVD-grown graphene to fabricate a whole 4-inch wafer with 52 chips on it. Rigid GFETs, fabricated on different substrates, with a variety of channel geometries (width/length), reveal a linear relation between the transconductance and the width/length ratio. The area normalized electrolyte-gated transconductance is in the range of 1-2 mS V$^{−1}$ $\Box$, and does not strongly depend on the substrate. Influence of the ionic strength on the transistor performance is investigated as a part of the work. Double contacts are found to decrease the effective resistance and the transfer length, but do not improve the transconductance. An electrochemical annealing/cleaning effect is investigated and proposed to originate from the out-of-plane gate leakage current. The devices are used as a proof-of-concept for bioelectronic sensors, recording external potentials from $\textit{ex vivo}$ heart tissue and $\textit{in vitro}$ cardiomyocyte-like cells (HL-1). Via multichannel measurements we are able to record and analyze both difference in action potentials as well as their spatial propagation through the chip. The recordings show distinguishable action potentials with a signal to noise ratio over 14 from $\textit{ex vivo}$ tissue and over 6 from the cardiac-like cell line $\textit{in vitro}$. Furthermore, I accomplished $\textit{in vitro}$ recordings of neuronal signals with a distinguishable bursting activity for the first time. [...]

Note: RWTH Aachen, Diss., 2017

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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

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