Fabrication and Characterization of Evanescent Microwave Probes Compatible With Atomic Force Microscope for Scanning Near-Field Microscopy

2002 ◽  
Author(s):  
Yaqiang Wang ◽  
Massood Tabib-Azar
Keyword(s):  
Atomic Force Microscope ◽  
Near Field ◽  
Planar Waveguides ◽  
Surface Measurement ◽  
Microwave Measurement ◽  
Contact Mode ◽  
Atomic Force ◽  
Afm Imaging ◽  
Microwave Probes

The design and microfabrication of silicon co-axial evanescent microwave probes (EMP) compatible with atomic force microscope (AFM) imaging was discussed. Scanning EMP (SEMP) imaging is suitable for nondestructive surface and subsurface characterization of materials over a wide frequency range-between 0.1 GHz and 140 GHz. The microfabricated EMP consists of a silicon V-shaped cantilever beam, a co-axial tip, and aluminum co-planar waveguides. The coaxial tip has an apex radius of ∼80 Å. The tip itself is oxidation-sharpened heavily-doped silicon surrounded by an oxide layer that acts as insulator and covered with an aluminum co-axial layer. The tip apex is electrically connected to a strip of aluminum that forms the active part of the waveguide. The design and microfabrication procedure are described. Mechanical and electrical characterizations are discussed. Contact mode and SEMP surface measurement results are reported. The first ever simultaneous contact AFM and scanning near-field microwave microscopy (SNMM) surface imaging are presented. Using the microwave measurement along with the AFM imaging opens up a new window to see inside the materials and sets the stage for hyperspectral imaging of organelles of biological objects as well as electronic devices and structural materials.

Characterization of Uniformity and Reproducibility of Photoresist Nanomasks Fabricated by Near-Field Scanning Optical Nanolithography

2006 ◽  
Vol 6 (11) ◽  
pp. 3647-3651 ◽  
Author(s):  
Sangjin Kwon ◽  
Youngmo Jeong ◽  
Sungho Jeong
Keyword(s):  
Silicon Substrate ◽  
Near Field ◽  
Pattern Transfer ◽  
Contact Mode ◽  
Positive Photoresist ◽  
Atomic Force ◽  
Optical Nanolithography ◽  
Nanochannel Array ◽  
Near Field Scanning

The uniformity and reproducibility of the photoresist nanopatterns fabricated using near-field scanning optical nanolithography (NSOL) are investigated. The nanopatterns could be used as nanomasks for pattern transfer on a silicon wafer. In the NSOL process, uniform patterning with high reproducibility is essential for reliable transfer of the mask patterns on a silicon substrate. Using an aperture type cantilever nanoprobe operated at contact mode and a positive photoresist, various nanopatterns are produced on thin photoresist layer coated on the silicon substrate. The size and shape variations of thereby produced patterns are investigated using atomic force microscope to determine their uniformity and reproducibility. It is demonstrated that the NSOL-produced photoresist nanomasks can be successfully applied for silicon pattern transfer by fabricating a silicon nanochannel array.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

scholarly journals Redesigned Sensor Holder for an Atomic Force Microscope with an Adjustable Probe Direction

2021 ◽  
Author(s):  
Janik Schaude ◽  
Maxim Fimushkin ◽  
Tino Hausotte
Keyword(s):  
Atomic Force Microscope ◽  
Piezoelectric Actuator ◽  
High Speed ◽  
Closed Loop ◽  
Coefficient Of Thermal Expansion ◽  
Measuring System ◽  
Contact Mode ◽  
Loop Control ◽  
Atomic Force ◽  
Measuring Machine

AbstractThe article presents a redesigned sensor holder for an atomic force microscope (AFM) with an adjustable probe direction, which is integrated into a nano measuring machine (NMM-1). The AFM, consisting of a commercial piezoresistive cantilever operated in closed-loop intermitted contact-mode, is based on two rotational axes, which enable the adjustment of the probe direction to cover a complete hemisphere. The axes greatly enlarge the metrology frame of the measuring system by materials with a comparatively high coefficient of thermal expansion. The AFM is therefore operated within a thermostating housing with a long-term temperature stability of 17 mK. The sensor holder, connecting the rotational axes and the cantilever, inserted one adhesive bond, a soldered connection and a geometrically undefined clamping into the metrology circle, which might also be a source of measurement error. It has therefore been redesigned to a clamped senor holder, which is presented, evaluated and compared to the previous glued sensor holder within this paper. As will be shown, there are no significant differences between the two sensor holders. This leads to the conclusion, that the three aforementioned connections do not deteriorate the measurement precision, significantly. As only a minor portion of the positioning range of the piezoelectric actuator is needed to stimulate the cantilever near its resonance frequency, a high-speed closed-loop control that keeps the cantilever within its operating range using this piezoelectric actuator further on as actuator was implemented and is presented within this article.

scholarly journals Design and Fabrication of a High-Speed Atomic Force Microscope Scan-Head

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 362
Author(s):  
Luke Oduor Otieno ◽  
Bernard Ouma Alunda ◽  
Jaehyun Kim ◽  
Yong Joong Lee
Keyword(s):  
Atomic Force Microscope ◽  
Natural Frequency ◽  
High Speed ◽  
Contact Mode ◽  
Ongoing Process ◽  
Atomic Force ◽  
Constant Height ◽  
Mode Tracking

A high-speed atomic force microscope (HS-AFM) requires a specialized set of hardware and software and therefore improving video-rate HS-AFMs for general applications is an ongoing process. To improve the imaging rate of an AFM, all components have to be carefully redesigned since the slowest component determines the overall bandwidth of the instrument. In this work, we present a design of a compact HS-AFM scan-head featuring minimal loading on the Z-scanner. Using a custom-programmed controller and a high-speed lateral scanner, we demonstrate its working by obtaining topographic images of Blu-ray disk data tracks in contact- and tapping-modes. Images acquired using a contact-mode cantilever with a natural frequency of 60 kHz in constant deflection mode show good tracking of topography at 400 Hz. In constant height mode, tracking of topography is demonstrated at rates up to 1.9 kHz for the scan size of 1μm×1μm with 100×100 pixels.

Heat Transfer Spectroscopy and “Heat Transfer-Distance” Curves

2008 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Sheng Shen ◽  
Gang Chen
Keyword(s):  
Heat Transfer ◽  
Radiative Transfer ◽  
Atomic Force Microscope ◽  
Near Field ◽  
Surface Force ◽  
Casimir Forces ◽  
Distance Curve ◽  
Transfer Distance ◽  
Atomic Force ◽  
Order Of Magnitude

Thermal radiative transfer between objects as well as near-field forces such as van der Waals or Casimir forces have their origins in the fluctuations of the electrodynamic field. Near-field radiative transfer between two objects can be enhanced by a few order of magnitude compared to the far-field radiative transfer that can be described by Planck’s theory of blackbody radiation and Kirchoff’s laws. Despite this common origin, experimental techniques of measuring near-field forces (using the surface force apparatus and the atomic force microscope) are more sophisticated than techniques of measuring near-field radiative transfer. In this work, we present an ultra-sensitive experimental technique of measuring near-field using a bi-material atomic force microscope cantilever as the thermal sensor. Just as measurements of near-field forces results in a “force distance curve”, measurement of near-field radiative transfer results in a “heat transfer-distance” curve. Results from the measurement of near-field radiative transfer will be presented.

Anin situatomic force microscope for normal-incidence nanofocus X-ray experiments

2016 ◽  
Vol 23 (5) ◽  
pp. 1110-1117 ◽  
Author(s):  
M. V. Vitorino ◽  
Y. Fuchs ◽  
T. Dane ◽  
M. S. Rodrigues ◽  
M. Rosenthal ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Force Microscope ◽  
High Speed ◽  
Normal Incidence ◽  
Organic Thin Film ◽  
X Ray ◽  
Atomic Force ◽  
Synchrotron Beamlines

A compact high-speed X-ray atomic force microscope has been developed forin situuse in normal-incidence X-ray experiments on synchrotron beamlines, allowing for simultaneous characterization of samples in direct space with nanometric lateral resolution while employing nanofocused X-ray beams. In the present work the instrument is used to observe radiation damage effects produced by an intense X-ray nanobeam on a semiconducting organic thin film. The formation of micrometric holes induced by the beam occurring on a timescale of seconds is characterized.

A Finite-Impulse-Response-Based Approach to Control Acoustic-Caused Probe-Vibration in Atomic Force Microscope Imaging

2017 ◽  
Author(s):  
Sicheng Yi ◽  
Qingze Zou
Keyword(s):  
Atomic Force Microscope ◽  
Impulse Response ◽  
Controller Design ◽  
Finite Impulse Response ◽  
Feedforward Control ◽  
Acoustic Noise ◽  
Noise Cancellation ◽  
Control Approach ◽  
Atomic Force ◽  
Afm Imaging

In this paper, we propose a finite-impulse-response (FIR)-based feedforward control approach to mitigate the acoustic-caused probe vibration during atomic force microscope (AFM) imaging. Compensation for the extraneous probe vibration is needed to avoid the adverse effects of environmental disturbances such as acoustic noise on AFM imaging, nanomechanical characterization, and nanomanipulation. Particularly, residual noise still exists even though conventional passive noise cancellation apparatus has been employed. The proposed technique exploits a data-driven approach to capture both the noise propagation dynamics and the noise cancellation dynamics in the controller design, and is illustrated through the experimental implementation in AFM imaging application.

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