Nano-R™ Atomic Force Microscope
The Nano-R™ is a general purpose atomic force microscope (AFM) for making routine images on structures with nanometer sized features. Because the Nano-R™ can be used with two versions of image acquisition software, X'Pert™ software and EZMode™, it is optimized for novices, casual users, and routine users. Further, the Nano-R™ is supplied with the most commonly used AFM modes including contact, lateral force, material sensing, non-contact and close contact mode. The three primary subsystems of the Nano-R™ AFM are the master computer, a control unit, and the Nano-R™ stage.
Nano-R™ Atomic Force Microscope Enlarged
The Pacific Nanotechnology Nano-R™ AFM sets a new standard in atomic force microscopy for nanotechnology, nanoscience and nanoinspection applications. It is designed to make the highest quality images and measurements of materials and structures with nanometer scale dimensions. The Nano-R™ is ideal for both independent researchers and for research teams that want to share an AFM.
The Nano-R™ AFM stage (Figure 1 shown at the left) is a tabletop unit and can be operated with high resolution results in a normal laboratory environment. The stage is optimized for rapidly exchanging samples and probes. Once a sample is placed in the stage placing the probe above the sample is rapidly done with the automated X-Y stage and the high resolution video microscope. Inside the Nano-R™ AFM stage are the AFM scanner, X-Y positioning stage and a video microscope. Cables are attached to the stage in the rear.
Figure 1: The Nano-R™ Stage
The AFM Scanner
The Nano-R™ AFM scanner (Figure 2) uses the standard light lever method for monitoring the motion of a cantilever as it is raster scanned across a surface. The scanner is a patented, compact design that offers a direct internal scanner calibration and a hollow pivot scanner that facilitates a direct view with a video microscope. Alignment of the AFM sensor is achieved with four adjustment screws that are easily accessed at the front of the AFM head. Two of the adjustments move the laser onto the cantilever and two of the adjustments move the photo-detector into the path of the reflected laser beam.
Figure 2: Nano-R™ AFM Scanner
The Sample Holder
The Nano-R™ sample holder facilitates the rapid introduction of a sample to the microscope stage.† The holder can accommodate a large variety of sample sizes. The standard sample holder is for standard magnetic disks.
Figure 3: Nano-R™ Sample Puck
The Nano-R™ multiple thickness puck is designed to accommodate samples of several thicknesses. The puck is made from several ¼" (6.35 mm) thick metal plates that are each 2" (50.8 mm) in diameter. The bottom plate slides into the Nano-R™ X-Y positioner.† The remaining plates (up to four) may be attached to the bottom plate with screws. Each of the plates has a magnet at its center for securing a sample onto the puck.
|Config.||Thickness||Total Height||Sample Thickness Range|
|Base||0.25" (6.35 mm)||0.25" (6.35 mm)||1.00" - 1.30" (25.40 mm - 33.02 mm)|
|1 Plate||0.25" (6.35 mm)||0.50" (12.70 mm)||0.75" - 1.05" (19.05 mm - 26.67 mm)|
|2 Plates||0.25" (6.35 mm)||0.75" (19.05 mm)||0.50" - 0.80" (12.70 mm - 20.32 mm)|
|3 Plates||0.25" (6.35 mm)||1.00" (25.40 mm)||0.25" - 0.55" (06.35 mm - 13.97 mm)|
|4 Plates||0.25" (6.35 mm)||1.25" (31.75 mm)||0.00" - 0.30" (00.00 mm - 7.62 mm)|
There are several optional sample holders
for the Nano-R™. Additionally, customers can fabricate their own sample "pucks". The maximum sample size that the Nano-R™ stage can hold is 3½" × 3½".
Automated X-Y Translation Stage
The motorized X-Y positioning stage is used for moving the sample on the "puck" under the AFM probe. The X-Y positioning stage may be activated from a window on the master computer, or it may be activated from a "track ball".
Video Optical Microscope†
A color video microscope is essential in an AFM for locating features on a surface for scanning. The Nano-R™ AFM has a motorized zoom and focus video microscope that is controlled by either software or the system's trackball. There is a manual control of the X-Y position of the microscope objective for centering the image of the cantilever in the video microscope image.
Figure 4: Optical microscope image of an AFM cantilever in the Nano-R™
Probe Exchange Mechanism
The Nano-R™ has a unique probe exchange mechanism
that does not require that the AFM scanner be removed from the AFM stage. There is no chance of the AFM scanner being dropped and damaged when using the probe exchange mechanism.
Figure 5: Probe exchange mechanism
Nano-R™ Controller & Master Computer
The master computer, which is a standard PC unit, is required for acquiring and analyzing images. The computer and the control unit are connected with a standard Ethernet connector. Specifications for the computer system are improved on a routine basis when new computer systems are made available.
Nano-R™ Controller & Master Computer
The architecture of the control unit for the Nano-R™ AFM is based on a PC micro-controller and is connected to the master computer though a standard Ethernet port.
The Nano-R™ has two software modules that are provided with the system: a module for acquiring images and a module for displaying and analyzing images. Additionally, there are advanced modules available as options for displaying and analyzing images. See datasheet #P-000-7331-0.
Image Capture Software
The Nano-R™ has two types of image capture software. The first type is for beginning users and the second is for more advanced users. EZMode™ software is ideal for new Nano-R™ operators or operators that want to use the instrument on an occasional basis. The X'Pert™ software gives powerful control over the Nano-R™ and is designed for expert AFM users.
EZMode™ software is a sequential software package that guides you through the process of acquiring an AFM image. The process oriented software gives a step-by-step procedure for getting an AFM image. At the top of the EZMode™ screen is a list of the steps that must be followed.
Figure 1: EZMode™ Software Interface
The following steps are provided in the EZMode™ software.†By following these steps it is possible for even the most inexperienced operated to get an AFM image:
Assure that a cantilever is in the Microscope.
- Start: Calibrate Scanner (optional): Select "linearize", then "scanner auto-linearity".
- Select Mode: Contact Mode or Vibrating Mode.
- Align Laser: Align the laser onto the cantilever.
- Frequency Sweep: Automatic peak detection for vibrating mode imaging. (only in vibrating mode)
- Stage: Move sample until desired scan area is under cantilever.
- Tip Approach: Activate the motors for approaching the sample with the probe.
- Scanner Sample: Set the scan size and scan parameters.
- Image Processing: Visualize and analyze images.
- Tip Retract: Withdraw tip when scan is complete.
Direct control of the available feature in an "interactive" mode is possible with the X'Pert™ software.
Figure 2: X'Pert Mode™ Software Interface
The menu items that are available in the X'Pert™ software are:
- Setup: This window contains all of the control parameters for operating the microscope including scan ranges, PID settings, etc.
- Tip: The tip button controls all aspects of the tip approach to the sample. The type of approach, rate of approach, and withdrawal are controlled.
- Scanner Control: This window is used while scanning a sample. The window shows between 1 and 4 windows and has the scan size, speed, PID setting, and other scan parameters.
- Force/Distance Window: Complete control of Force/Position curves is possible with the force position curve window.
All of the commonly available image analysis techniques come as standard features with the Nano-R™ AFM system.
Functions that are available are:
- Histogram Adjust
- Image Level
- 3-D Display
- Line Profile
- Image Correct
Nano-R™ Image Analysis Software
Each of the AFM image analysis software features is activated with an icon at the top of the analysis window. Software features include:
- Image Leveling: This window permits the removal of sample tilt from images. Removal methods include 3 point plane, polynomial plane fit and 1D line leveling. User specified areas may be selected and excluded from the leveling process.
- Line Profiles: Several types of line profiles may be selected. They include Horizontal, Vertical, Oblique, Polygonal, Circular, and several line average. Up to four line profiles may be selected for analysis. Horizontal and vertical distances may be calculated on the line scans.
- Histogram Analysis: The histogram analysis feature is useful for optimizing the display of AFM images. A region of the image histogram may be selected and used for the full pallet range of a displayed image.
- Filtering: Several filtering functions may be applied to an AFM image. Filter options include the blur function, a predetermined filter function, and a conventional kernel. It is possible to select areas of the image that are not included in the filter process.
- Fourier Filtering: A standard FFT function may be applied to an image.
- 3D Imaging: The 3-D imaging feature images may be viewed from several angles and perspectives. Simply dragging the mouse over the image changes the viewing angles.
Specifications for the Nano-R™ AFM
- X-Y Scan:
- Range: 80 µm
Resolution: 0.1 nm
- Range: 8 µm
Resolution: 0.1 nm
Z Noise: 0.13 nm Calibration sensors on
0.07 nm Calibration sensors off
- Color Video Microscope:
- Magnification (9" monitor): 1000x
Motorized Zoom/Focus: 4x
Field of View: 140 µm x 190 µm
Resolution: 1.5 µm
- Automated X-Y Stage:
- Range: 25.4 x 25.4 mm
Step Size: 3 µm
Slew Rate: 1.2 mm/sec.
- Scan Modes:
- Ч Contact Mode
Ч Lateral Force Mode
Ч Close-Contact Mode
Ч Non-Contact Mode
Ч Material Sensing Mode
Ч Force/Distance Mode
- Master Computer:
- CPU >1 GHz
CPU Hard Drive >20GB
RAM Memory 256 MB
- Physical Specifications: (in./lbs.)
Nano-R™ Sample Holders
The unique Nano-R™ sample holder is designed so that it can accommodate many types and sizes of samples. The sample holder that comes standard with the Nano-R™ is 2 inches in diameter and 1.25 inches tall.
On the top of the sample holder is a magnetic plate that holds sample disks. A drawing showing the dimension of the sample holder as well as a photograph of the sample holder is shown in below.
Standard Sample holder
Examples of modifications of the sample holder to accommodate different types of samples include:
Holder for MTS Nanoindenter Sample
The MTS Nanoindenter has a sample holder that is an aluminum cylinder. The Nano-R™ sample holder was easily modified to accommodate the MTS sample holder. With the modification it is easy to rapidly move samples from the Nanoindenter to the Nano-R™ AFM.
Holder for MTS Nanoindenter Sample
Addition of X-Y-Z micropositioner for electrical probing
By adding an X-Y-Z micropositioner to the sample holder, an electrical test stage can be created. A test probe can be attached to the positioner. Then the test probe (or probes) can be placed on a sample. The entire sample holder/positioner assembly can then be placed into the Nano-R™ AFM.
X-Y-Z Micropositioner for Electrical Probing
Dual X-Y-Z†Micropositioner for Electrical Probing
Nano-R™ Probe Exchange Mechanism
The Nano-R™ has a unique probe exchange mechanism that does not require that the AFM scanner be removed from the AFM stage.† There is no chance of the AFM scanner being dropped and damaged with the probe exchange mechanism
The Nano-R™ is shown here imaging the cross section of a sample. The sample is mounted on the versatile AFM puck.
To exchange the AFM probe, the sample puck is removed from the AFM stage. The knobs at the left and right are rotated to release the AFM head from the stage.
The AFM scanner can then be rotated so that the AFM probe can be accessed and easily exchanged.