Asylum
Research, the technology leader in Scanning Probe and Atomic Force Microscopy
(SPM/AFM), has announced a new grant program for early adopters to explore the
capabilities and applications of the unique new Band Excitation technique. Existing
or new Asylum AFM users are encouraged to apply for grants valued at up to $50,000
USD. Additional information on grant submission content and procedures is provided
at www.asylumresearch.com/grants.
Operational principle of the BE method in SPM. The excitation signal is digitally synthesized to have a predefined amplitude and phase in the given frequency window. The cantilever response is detected and Fourier transformed (FFT) at each pixel in an image. The ratio of the fast FFT of response and excitation signals yields the cantilever response (transfer function). Fitting the response to the simple harmonic oscillator yields amplitude, resonance frequency, and Q-factor that are plotted to yield 2D images, or used as feedback signals. Reprinted with permission (Nanotechnology 18 (43) (2007)).
“The R&D 100 Award-winning Band Excitation (BE) technique has shown
great promise in mapping the conservative interactions, nonlinearities, and
energy dissipation of materials on the nanoscale,” said Roger Proksch,
Asylum Research President and grants lead. “Stephen Jesse and Sergei Kalinin
at Oak Ridge National Laboratory (ORNL), collaborating with Asylum Research,
have developed the BE system where a synthesized excitation signal probes the
response of a cantilever at multiple frequencies simultaneously. This method
is a fast and sensitive technique which may be useful for understanding and
mitigating energy losses in magnetic, electrical, and electromechanical processes
and technologies. We encourage new and existing AFM users to apply for the BE
grants and to work closely with the Asylum team to blaze new trails with this
exciting new technique.”
Suggested grant topics include:
- Energy dissipation in materials.
- Contact resonance measurements for materials properties contrast
and quantification.
- Electromechanical properties of materials, including piezo- and
ferroelectrics.
- Applications of BE to solar materials – photovoltaics and
energetic materials.
- BE methodologies applied to other active probes, such as localized
thermal analysis.
- Biological materials including mechanical properties and recognition
mechanisms.
- Advanced methodologies for data reduction and analysis.
- Probing nonlinear tip-sample interactions.
- Other nanoscale measurements that can benefit from rapid multiple
frequency measurements.
“Classical scanning probe microscopies are based on the excitation and
detection of single or, recently, dual frequencies. In doing so, the information
on real tip-surface interactions manifested in the fine details of the resonance
curve shape is not measured. Implementation of BE on multiple ambient and UHV
systems at ORNL has allowed us to achieve several technical breakthroughs in
mapping structure, magnetic and electrical dissipation, and electromechanical
activity in ferroelectric, multiferroic, and biological systems in ambient,
liquid, and vacuum environments,” commented Sergei Kalinin.
Added Stephen Jesse, “Classical SPM offers basically a gray-scale image
of cantilever dynamics at a single frequency. Band excitation opens a new and
colorful multi-frequency view of the nanoworld that we can already explore,
but are just starting to appreciate”.