scholarly journals Development of a Metrological Atomic Force Microscope System with Improved Signal Quality

2021 ◽  
Vol 6 (1) ◽  
pp. 49
Author(s):  
Yiting Wu ◽  
Elisa Wirthmann ◽  
Ute Klöpzig ◽  
Tino Hausotte
Keyword(s):  
Laser Beam ◽  
Atomic Force Microscope ◽  
Optical Design ◽  
Wedge Angle ◽  
Three Dimensional ◽  
Measuring System ◽  
Measuring Head ◽  
Atomic Force ◽  
Design Program ◽  
Reflecting Surface

This article presents a new metrological atomic force microscope (MAFM) with a homodyne interferometer and a tilt measuring system by a position sensitive device (PSD). The combination allows simultaneous three-dimensional detection of the tip displacement by capturing the position, bending and torsion of a reflecting surface of the cantilever realized with one laser beam. Based on an existing interferometric measuring head of a micro-tactile 3D probe, the sensor head was revised and adapted for atomic force microscopy. The new measuring system uses two tiltable plane mirrors to adjust the direction and position of a focused laser beam. With this adjustment unit, the focused laser beam can be steered perpendicular to the reflecting backside of the cantilever. Regarding the probe system, the optical design of the measuring head has been reengineered to reduce the disturbing interference on the PSD. A simulation applying the optical design program OpticStudio from Zemax shows that the integration of two wedge plates with a wedge angle of 0.5° reduces the disturbing interference significantly. After manufacturing, initial measurement results are presented to verify the functionality.

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.

The atomic-force microscope and its future in biology

1993 ◽  
Vol 51 ◽  
pp. 704-705
Author(s):  
Jean-Paul Revel
Keyword(s):  
Silicon Nitride ◽  
Laser Beam ◽  
Atomic Force Microscope ◽  
Scanning Tunneling Microscope ◽  
Point Of View ◽  
Scanning Tunneling ◽  
Close Relative ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

A Study of the Photoelectric Effect Caused by a Laser Beam Used in a Beam Bounce Technique in a C-AFM System

2008 ◽  
Author(s):  
Hung-Sung Lin ◽  
Mong-Sheng Wu
Keyword(s):  
Laser Beam ◽  
Failure Analysis ◽  
Atomic Force Microscope ◽  
Photoelectric Effect ◽  
Scanning Probe ◽  
Nanometer Scale ◽  
Electrical Characteristics ◽  
Atomic Force ◽  
Probe Microscope ◽  
Probe Head

Abstract The use of a scanning probe microscope (SPM), such as a conductive atomic force microscope (C-AFM) has been widely reported as a method of failure analysis in nanometer scale science and technology [1-6]. A beam bounce technique is usually used to enable the probe head to measure extremely small movements of the cantilever as it is moved across the surface of the sample. However, the laser beam used for a beam bounce also gives rise to the photoelectric effect while we are measuring the electrical characteristics of a device, such as a pn junction. In this paper, the photocurrent for a device caused by photon illumination was quantitatively evaluated. In addition, this paper also presents an example of an application of the C-AFM as a tool for the failure analysis of trap defects by taking advantage of the photoelectric effect.

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.

Position measuring system in metrological atomic force microscope

2012 ◽  
Vol 20 (4) ◽  
pp. 796-802 ◽  
Author(s):  
李伟 LI Wei ◽  
高思田 GAO Si-tian ◽  
卢明臻 LU Ming-zhen ◽  
施玉书 SHI Yu-shu ◽  
杜华 DU Hua
Keyword(s):  
Atomic Force Microscope ◽  
Measuring System ◽  
Atomic Force

The Nano Membrane-Like Structure of the Precambrian Microfossils under Atomic Force Microscope (AFM)

2007 ◽  
Vol 121-123 ◽  
pp. 739-742 ◽  
Author(s):  
H.M. Chi ◽  
Z.D. Xiao ◽  
Xin Xing Xiao
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Atomic Force Microscope ◽  
Early Life ◽  
Three Dimensional ◽  
New Method ◽  
Subcellular Structure ◽  
Atomic Force ◽  
Fossil Embryos ◽  
Scanning Electron

Weng`an fauna in Guizhou, China provides a unique window for the evolution of the early life especially since the animal embryos and sponge is found there. Phosphatization makes the fossils preserve in details including cells and subcellular structure. Here we use atomic force microscope observing the surface of some three dimensional preserved embryo fossils and the ultra membrane-like structure is found under atomic force microscope (AFM) while such structure can`t be found under scanning electron microscope (SEM). The membrane-like structure is approximately 10nm in thickness which maybe one part of the fossil embryos or belong to another nano scale microfossils. Therefore, AFM provides a new method for the study of the ultra structure of the microfossils from Weng`an fauna.

Machining Complex Three-Dimensional Nanostructures With an Atomic Force Microscope Through the Frequency Control of the Tip Reciprocating Motions

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Yanquan Geng ◽  
Yongda Yan ◽  
Emmanuel Brousseau ◽  
Xing Cui ◽  
Bowen Yu ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Force Feedback ◽  
Normal Load ◽  
Frequency Control ◽  
Three Dimensional ◽  
Atomic Force ◽  
Combined Control ◽  
Novel Method ◽  
Lateral Displacements ◽  
Floor Surfaces

A novel method relying on atomic force microscope (AFM) tip based nanomachining is presented to enable the fabrication of microchannels that exhibit complex three-dimensional (3D) nanoscale floor surface geometries. To achieve this, reciprocating lateral displacements of the tip of an AFM probe are generated, while a high-precision stage is also actuated to move in a direction perpendicular to such tip motions. The width and length of microchannels machined in this way are determined by the amplitude of the tip motion and the stage displacement, respectively. Thus, the processing feed can be changed during the process as it is defined by the combined control of the frequency of the tip reciprocating motions and the stage speed. By employing the built-in force feedback loop of conventional AFM systems during such operations, the variation of the feed leads to different machined depths. Thus, this results in the capability to generate complex 3D nanostructures, even for a given normal load, which is set by the AFM user prior to the start of the process. In this paper, the fabrication of different microchannels with floor surfaces following half triangular, triangular, sinusoidal, and top-hat waveforms is demonstrated. It is anticipated that this method could be employed to fabricate complex nanostructures more readily compared to traditional vacuum-based lithography processes.

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