Open Positions

3D Graphene Electrodes for Energy Storage Devices

The extensive spreading and popularity of portable electronics as well as the future demand of electric vehicles will require the development of more sophisticated energy storage devices like batteries and supercapacitors. Graphene, a single sheet of sp² bonded carbon atoms arranged in a honeycomb crystal lattice, is seen as a suitable candidate for the production of carbon-based supercapacitors and batteries able to provide both high power and high energy density. Indeed, graphene's unique properties like high conductivity, chemical stability, and high surface to volume ratio, fulfill the most essential requirements for achieving electrodes with a high electrical double layer capacitance. The facile combination of graphene with highly conductive polymers or metal oxides to obtain additional pseudocapacitance makes graphene one of the most promising candidates for energy storage devices.

As the available surface area of one single graphene sheet on an electrode is strongly limited, the fabrication of a three-dimensional porous graphene structure is of high relevance. This master thesis will focus on the fabrication of graphene “foam” by chemical vapor deposition using a nickel scaffold. This method enables us to obtain a free-standing 3D graphene structure of high crystalline quality. The absence of any chemical contamination compared to the usual approach of the chemical reduction of graphene oxide allows us to harness all advantages of graphene, increasing the capacitance as well as the performance of graphene-based supercapacitors.

sem picture of graphene foam raman signal of graphene foam

Left: SEM micrograph of a graphene ”foam”. Middle: Raman spectra of a 3D graphene “foam” and a high quality single layer graphene film grown on copper foil. Right: Characterization of a graphene foam electrode in an electrochemical cell.

Planned activities:

  • Growth of graphene foam by chemical vapor deposition and its characterization by scanning electron microscopy and Raman spectroscopy
  • Fabrication of electrodes for supercapacitors
  • Characterization of the supercapacitors by cyclic voltammetry, charge-discharge measurements in an electrochemical cell using different electrolytes.

Start date: Fall/Winter 2015

For further information please contact Simon Drieschner.

Biosensing platform based on graphene solution-gated field-effect transistors modified with lipid bilayers

Graphene-based solution-gated field-effect transistors (SGFETs) are promising candidates for biosensing applications due to their high transconductance, chemical stability and their low electronic noise. However, to enable the specific detection of a particular analyte (e.g. streptavidin), the graphene SGFETs have to be modified. One possibility is the use of lipid bilayers on top of the graphene. Lipid bilayers can be easily formed on the active area of the graphene SGFET and could allow the integration of numerous transmembrane proteins.

The aim of this master project is to investigate the influence of different lipid bilayers on the transistors and to explore the incorporation of different proteins into the lipid layer to build biosensors for specific analytes. The work includes the growth of graphene, the device fabrication (including optical and e-beam lithography in the cleanroom), the formation of lipid bilayers and the detailed characterization of the devices.

Available in Spring 2015

For further information please contact Jose Antonio Garrido and Benno Blaschke

Flexible graphene electronics for neural implants

Since graphene is chemically very stable, flexible and biocompatible graphene field-effect transistors (FET) hold great promise for biosensing applications. Especially for the in-vivo detection of cell signals, where flexible devices are a key requirement, flexible graphene SGFETs could be the basis of a new generation of neural implants.

The aim of this master project is to further improve the fabrication and the device design of flexible graphene SGFETs. Furthermore, a new setup to investigate the influence of bending on the device performance will be built during the thesis. The fabricated devices will be used for the detection of cell signals. The student will be trained in graphene growth, cleanroom work, optical lithography and electronic characterization of graphene SGFETs.

Available in Spring 2015

For further information please contact Jose Antonio Garrido and Benno Blaschke

TUM Technische Universität München TUM Technische Universität München Physik Department Elektrotechnik und Informationstechnik TUM Technische Universität München
 

Upcoming Events

3.06.2013  
Benno Blaschke
Graphene SGFETs for biosensing applications

poster, Graphene Week 2013, Chemnitz, Germany

 

6.06.2013  
Jose A. Garrido
Graphene sensors for bioelectronic applications

plenary talk, Graphene Week 2013, Chemnitz, Germany

 

3.09.2013  
Roberta Caterino 
Novel functionalization of diamond surfaces for protein-based hybrid systems

talk, International Conference on Diamond and Carbons Materials, Riva del Garda, Italy

 

5.09.2013 
Roberta Caterino
Bio-photovoltaics based on hybrid systems of reaction centers and diamond

talk, International Conference on Diamond and Carbons Materials, Riva del Garda, Italy