High Resolution Atomic Force Microscope For Research
The HR AFM is an Advanced yet affordable AFM for researchers that need the highest resolution scanning capabilities. It is ideal for researchers that need to visualize and measure nanometer or sub-nanometer sized surface features.
* Prices vary depending on options purchased, importation taxes, and installation - training fees.
With a noise floor of 35 picometers, the HR AFM is capable of measuring samples with features from nano-meters to microns.
Kinematic Tip Approach
A stable kinematic design for probe approach is used in the HR AFM. An optional direct drive approach is available.
Research Grade Top View Video Optical Microscope
With a mechanical 7:1 zoom and a resolution of 2 µm the video optical microscope facilitates locating features, tip approach, and laser alignment.
Linearized piezoelectric scanners with several ranges are available to optimize scanning conditions.
The HR AFM uses industry standard lab view software. For customization, the systems VI's are readily available.
Once you buy the HR AFM you can add options and modes such as focus assist, image logger, lithography and liquid scanning when you are ready.
Simple Probe Exchange
With the removable probe holder, exchanging probes is simple, and takes less than a minute.
Ligh Lever Large Adjustment Range
Because the HR AFM has a large adjustment range on the laser and photodetector, probes from all major manufacturers can be used.
Side View Optic
Directly view the tip surface distance with the side view optic.
HR AFM Applications
Applications for the AFM include imaging:
Nanstructures (carbon nanotubes)
HR AFM Stage
The HR AFM stage has excellent thermal and mechanical stability required for high resolution AFM scanning. Additionally, its open design facilitates user modification.
Rigid Kinematic Design:
A three point support for the light lever makes the AFM less suceptable to vibrations, enabling ultra high resolution scanning.
Light Lever AFM Force Sensor:
Light lever force sensors are used in almost all AFM and permit many types of experiments.
Integrated Probe Holder/Probe Exchanger:
A unique probe holder and clipping mechanism allows quick and easy probe exchange.
Z Drive Options:
The standard HR AFM uses a single approach motor, the optional Z drive design uses four motors, enabling vertical approach and has a motorized video microscope.
The stage dimensions of 9" X 11" require little space and fit easily on a tabletop.
Precision XY Stage with Micrometer:
The sample is moved relative to the probe with a precision XY micrometer stage. Thus, the sample can be moved without touching it.
Modes Electric Plug:
A six pole electrical plug is located at the back of the stage to expand the capabilities of the HR AFM.
XYZ Precision Piezo Scanner:
The modified tripod design utilizes temperature compensated strain gauges which assure accurate measurements from images. Also, with this design it is possible to rapidly zoom into a feature visualized in an image.
Both the light lever laser and the photo detector adjustment mechanism may be directly viewed. This feature simplifies the laser/detector alignment.
Adaptable Sample Holder:
At the top of the XYZ scanner is a removable cap that holds the sample. The cap can be modified - or a new cap can be designed – to hold many types of samples.
Rapid Approach Control
The rapid approach control allows moving the probe from within a few hundred microns from the surface to a mm in less than a second. Below is side view video optical microscope view of the rapid approach control in the “stage down” and “stage up” positions.
In the stage down position, the probe is within a few hundred microns of the surface. Activating the Rapid Approach Control immediately lifts the probe away from the surface,
This a side view of the probe in the stage up position. In the up position the probe and sample are readily exchanged.
HR AFM EBox
Electronics in the HR AFM are constructed around industry-standard USB data acquisition electronics. The critical functions, such as XY scanning, are optimized with a 24-bit digital to analog converter. With the analog Z feedback loop, the highest fidelity scanning is possible. Vibrating mode scanning is possible with both phase and amplitude feedback using the high sensitivity phase detection electronics.
Scanning waveforms for generating motion in the XY axis with the piezo scanners are created with 24-bit DACS and HV amplifiers with 4 bits of gain control, giving 28 bits scanning. Feedback control using the XY strain gauges assures accurate tracking of the probe over the surface.
Phase and Amplitude Detector Circuit:
Phase and amplitude in the EBox are measured with highly stable phase and amplitude chips. The system can be configured to feed back on either phase or amplitude when scanning in vibrating mode.
At the rear of the EBox is a 50 pin ribbon cable that gives access to all of the primary electronic signals without having to open the EBox.
At the front of the EBox is a light panel that has seven lights. In the unlikely event of a circuit failure, these lights are used to determine the status of the EBox power supplies.
Precision Analog Feedback:
Feedback from the light lever force sensor to the Z piezoceramic is made using a precision analog feedback circuit. The position of the probe may be fixed in the vertical direction with a sample-and-hold circuit.
Variable Gain High Voltage Piezo Drivers:
An improved signal to noise ratio, as well as extremely small scan ranges are possible with the variable gain high voltage piezo drivers.
HR AFM Software
Software for acquiring images is designed with the industry standard LabVIEW™ programming visual interface instrument design environment. There are many standard functions, including setting scanning parameters, probe approach, frequency tuning, and displaying images in real time. LabVIEW™ facilitates rapid development for those users seeking to enhance the software with additional special features. LabVIEW also enables the HR AFM to be readily combined with any other instrument using LabVIEW.
All of the functions required before making a scan are on the pre-scan tab. This includes selecting the scan mode, red dot alignment, frequency scan, and automatic tip approach.
Images are acquired using the scanning tab. Parameters selected on the scanning tab include the scan size, scan rate, GPID parameters, and the color scale used for displaying images. Included with the scanning tab is an image buffer capability that facilitates in-zooming and out-zooming.
Software control for optional modes such as MFM, EFM, and advanced F/D are found in the modes tabs. The example shown here is of the advanced F/D mode tab. This allows fine control of all the parameters controlling acquisition of force-distance curves, as well as acquisition of F-D curve maps. Mapping of curve sin this way allows the user to locate and visualize regions of the sample with differing properties, such as presence of specific molecules, or mechanical properties.
Image Analysis Software
Included with the HR AFM is the Gwyddion open source SPM image analysis software. This complete image analysis package has all the software functions necessary to process, analyze, and display SPM images.
Visualization: false color representation with different types of mapping
Shaded, logarithmic, gradient- and edge-detected, local contrast representation, and Canny lines
OpenGL 3D data display: false color or material representation
Easily editable color maps and OpenGL materials
Basic operations: rotation, flipping, inversion, data arithmetic, crop, and resampling
General convolution filter with user-defined kernel
Statistical functions: Ra, RMS, projected and surface area, inclination, histograms, 1D and 2D correlation functions, PSDF, 1D and 2D angular distributions, Minkowski functionals, and facet orientation analysis
Statistical quantities calculated from area under arbitrary mask
Row/column statistical quantities plots
ISO roughness parameter evaluation
Grains: threshold marking and un-marking, and watershed marking
Grain statistics: overall and distributions of size, height, area, volume, boundary length, and bounding dimensions
Integral transforms: 2D FFT, 2D continuous wavelet transform (CWT), 2D discrete wavelet transform (DWT), and wavelet anisotropy detection
Fractal dimension analysis
Data correction: spot remove, outlier marking, scar marking, and several line correction methods (median, modus)
Removal of data under arbitrary mask using Laplace or fractal interpolation
Automatic XY plane rotation correction
Arbitrary polynomial deformation on XY plane
1D and 2D FFT filtering
Fast scan axis drift correction
Mask editing: adding, removing or intersecting with rectangles and ellipses, inversion, extraction, expansion, and shrinking
Simple graph function fitting, critical dimension determination
Force-distance curve fitting
Axes scale calibration
Merging and immersion of images
Tip modeling, blind estimation, dilation and erosion
HR AFM Video Microscope
The HR AFM includes 2 video optical microscopes for viewing the sample and probe. The video microscopes are essential for locating features on a surface, making a safe and efficient probe approach, and aligning the light lever force sensor.
Top View Video Microscope
From the top, the HR AFM has a research grade video optical microscope with a 7:1 mechanical zoom, a 5 MP camera, and a coaxial light. The with a resolution of < 2 microns, this microscope is ideal for locating features on a surface for scanning.
With a 7:1 mechanical zoom, it is possible to use a large field of view to locate features for imaging. It is then possible to zoom in to get very high resolution video microscope images.
Side View Video Microscope
A side view video microscope, has a 2 mp camera and an off axis LED light source. This camera is used for visualizing the distance between the probe and the sample. This microscope is especially helpful for assisting probe approach on clear samples as well as samples that don't reflect light.
HR AFM Probe Holder
The HR AFM utilizes a unique probe holder/exchange mechanism. Probes are held in place with a spring device that mates with a probe exchange tool. With the probe exchange tool, changing probes takes only a few minutes.
Quick and Easy AFM Probe Exchange
The probe holder insert is removed from the HR AFM.
R to L: Box of probes, probe exchange tool, and probe holder insert.
Activating the probe spring clip by applying light pressure.
HR AFM Image Gallery
The true measure of an AFM is the quality of images it measures. With a noise floor of less than 35 picometers, and 28 bit scanning resolution, the HR AFM is capable of measuring the highest resolution images on many types of samples including: polymers, 2-D samples, crystals, ceramics, bio molecules, biomaterials, and semiconductors.
Vibrating mode image of F10H20 measured with a 50 X 50 X 17 micron scanner.
The HR AFM includes the most commonly used AFM Modes. The are:
Vibrating Mode (tap)
Vibrating mode imaging is the most common mode for measuring topography images with an AFM. In vibrating mode the vibration amplitude of the probe is held constant during a scan. Adjustable parameters include the vibrating frequency, amplitude of vibration, and the amount of dampening of the vibrating probe.
In non-vibrating mode, commonly called contact mode, the deflection of a cantilever is held constant during scanning. This mode is often used for scanning in liquids and is also used for measuring force-distance curves.
Phase mode images are measured in vibrating mode and are useful for identifying different areas of hardness on a surface. The technique operates by measuring the phase change caused by differing materials on a surface while scanning.
Lateral force mode measures the local friction a probe senses as it is scanned across a surface. The friction can be caused by surface texture or by differing chemical composition.
Optional modes that can be purchased with the HR AFM include:
Measures surface magnetic field by incorporating a magnetic probe into the AFM. MFM is used to generate images of magnetic fields on a surface, and is particularly useful in the development of magnetic recording technology. Magnetic fields associated with individual magnetic nanoparticles are also revealed through MFM.
Electrostatic Force Microscopy (EFM) is a type of dynamic non-contact atomic force Microscope where the electrostatic force is probed. “Dynamic” here means that the cantilever is oscillating and does not make contact with the sample. This force arises due to the attraction or repulsion of separated charges.
Force Distance Curves measure the deflection of a cantilever as it interacts with a surface. Force-Distance measurements monitor such surface parameters as: Adhesion, Stiffness, Compliance, Hardness, and Contaminate Thickness. This advanced AFM module is flexible and enables many types of experiments.
The C-AFM measures topography and conductivity images simultaneously. This option allows measuring current-voltage (I/V) curves at specific locations on a surface.
This NanoLithography software option enables the AFM probe to alter the physical or chemical properties of the surface. Created in LabVIEW and integrated with the AFMControl software. VI's are available to customers who want to modify the software and create new capabilities.
In the STM, the current flow between a metal probe and a sample are used to control the distance between the conductive probe and conductive surface. When the probe is scanned across the surface, if the current between the probe and surface are held constant with a feedback control loop driving a piezo ceramic, the topography of the sample's surface in measured.
Open Liquid Cell
This option includes a special probe holder and open liquid cell for scanning samples submerged in liquids. The Dunk and Scan can directly replace the HR AFM probe holder.
HR AFM Options
Direct Drive Option
In the HR AFM with direct drive option, three motors are used move the plate that supports the light lever force sensor. When the probe approaches the surface, it moves directly onto the features viewed in the tip view optical microscope. The forth motor, controls the focus of the top view optical microscope. If all four motors are activated at the same time, the top view video optical microscope will state focused on the probe.
There are several benefits to the the 4 motor option for the HR AFM. The include:
Simulates direct drive tip approach.
Motorized control of probe sample angle.
Focusing on the probe during tip approach.
Sample to Probe focus with software control.
In the direct drive option, motor 1, 2, and 3 simultaneously move the Light lever plate up and down, and the motor 4 controls the optics focus.
The AFMWorkshop Q-Box filters both structural and acoustic vibrations and assures the highest resolution images. The Q-Box, constructed from medium density fiberboard has high density foam for filtering sound and a floating platform for filtering structural vibrations.
The HR AFM has a number of options to enhance its performance and expand its capabilities. These options may be purchased with a new AFM or at any time after the original purchase.
Measures the deflection of a cantilever as it interacts with a surface. Monitors parameters such as: Adhesion, Stiffness, Compliance, Hardness, and Contaminate Thickness. Advanced SPIP analysis software.