The following projects can be conducted in our group:
- Pulling Nano Pipettes for Scanning Ion Conductance Microscopy
Scaning Ion Conductance Microscopy (SICM) is one of the few methods available for 3D imaging of living cells with nanometer resolution. A crucial ingredient are pipettes with nanoscale apertures which are typically “pulled” from glass tubes. In this project the fabrication using a laser-based pipette puller is optimized and tested in the SICM device.
- Large Amplitude Effects in Dynamic Atomic Force Microscopy
This project aims at characterizing the nonlinear dynamics of the cantilever-surface system in dynamic atomic force microscopy (AFM). By measuring the frequency spectrum for varying tip-sample distance and oscillation amplitude, regimes of stable and unstable, chaotic oscillations are identified.
- Anharmonic Short-Range Interactions in Atomic Force Microscopy
During oscillation the tip of an atomic force microscope (AFM) samples the distance-dependent tip-sample interaction which results in a nonlinear response. By analyzing higher harmonics of the cantilever oscillation the interaction force is characterized for different surfaces.
- Metal-Coated Cantilevers for Optically Driven Dynamic Atomic Force Microscopy
Vibration modes of a cantilever in an atomic force microscope (AFM) can be excited by focusing a laser beam directly onto the microscale cantilever. This project aims at exploring customized cantilever coatings for optimized light-induced response.
- Deposition of Fluorophore Molecules on Surfaces in Ultra-High Vacuum
In order to investigate the dynamics of self-assembled organic layers on surfaces a controlled preparation protocol is essential. In this project a dedicated evaporator for deposition of molecules in an ultra-high vacuum (UHV) chamber is developed and tested, including in situ monitoring equipment. The evaporator is used for preparation of fluorophore layers on flat surfaces and the samples are characterized by scanning probe microscopy (SPM).
- Nonlinear Oscillation Dynamics of Atomic Force Microscopy Cantilevers
The amplitude spectrum of a cantilever in an atomic force microscope (AFM) in vicinity to a sample surface is rich in structure if the tip-sample interaction is sufficiently nonlinear. In this project the eigenfrequencies and mixing modes due to external forces for different cantilevers, as well as nonlinear mapping modes are explored.
- Mapping Light-Induced Forces on Nanostructures Samples
Light-matter interaction can lead to various phenomena such as optical forces, photovoltages, and plasmon excitation. In this project the possibility to map such effects with dynamic atomic force microscopy (AFM) is explored on nanostructured surfaces. Possible approaches are Kelvin probe force microscopy (KPFM), amplitude modulated force detection, or tip-induced light scattering in the near field.
- Long-Range Order of Self-Assembled Organic Molecules Prepared in Ultra-High Vacuum
Photoemission electron microscopy (PEEM) enabled simultaneous spatially and energy resolved investigation of the electronic and optical properties of dye molecules adsorbed on a surface. In this project a dedicated ultra-high vacuum (UHV) evaporator for molecular species is being built and used for well-controlled preparation of ultrathin fluorophore layers. The geometric, optical and electronic properties are investigated using atomic force microscopy (AFM), fluorescence microscopy, and PEEM.
- Mapping the Work Function of Heterogeneous Metal-Semiconductor Nanostructures
The spatially dependent work function of metal-semiconductor nanostructures at surfaces contains vital information on the material distribution and the band topology. Using Kelvin probe force microscopy (KPFM) or photoemission electron microscopy (PEEM) the work function can be mapped with high spatial resolution. This capability is applied to nanostructures prepared by evaporation in vacuum or by ex-situ nanolithography.
- Morphology of live cells on structured surfaces studied by Scanning Ion Conductance Microscopy (Biophysics)
Adhesion of cells to surfaces can include several steps such as migration, initial physical or chemical binding, rearrangements in the cells surface region, and spreading. The aim is to uncover surface structure dependent interaction mechanisms on the basis of time-dependent morphology studies.
For the State Examination ("Staatsexamen") a variety of projects are available which are closely related to running activities in our research group. Possible topics are:
- Dynamic atomic force microscopy (AFM)
- Growth of molecular nanostructures
- Luminescence properties of dye aggregates on surfaces
- Morphology of metallic nanostructures on surfaces
None at the moment.