ICSPI nGauge AFM User manual

User Manual
Version 1.1
Atomic Force Microscope

nGauge AFM User Manual 2
Table of Contents
Introduction ..................................................................................................................................................3
1.0 Safety and Precautions ........................................................................................................................... 3
2.0 Overview .................................................................................................................................................5
2.1 AFM Basics .......................................................................................................................................... 5
2.2 sc-AFM Basics...................................................................................................................................... 5
2.3 nGauge AFM Components.................................................................................................................. 6
2.4 nGauge AFM Capabilities and Limitations .......................................................................................... 6
3.0 Setup .......................................................................................................................................................6
3.1 Where to set it up ...............................................................................................................................6
3.2 How to set it up...................................................................................................................................7
3.3 Installing the Software ........................................................................................................................ 9
4.0 Basic Operation.....................................................................................................................................10
4.1 Software Overview............................................................................................................................10
4.2 Preparation and Approach................................................................................................................11
4.3 Imaging..............................................................................................................................................12
4.4 Analyzing Data ..................................................................................................................................14
5.0 Post-Processing..................................................................................................................................... 14
5.1 Gwyddion.......................................................................................................................................... 14
6.0 Troubleshooting....................................................................................................................................15
7.0 Advanced Controls................................................................................................................................17
7.1 Frequency Sweep - Advanced Controls ............................................................................................ 17
7.2 Approach - Advanced Controls .........................................................................................................18
7.3 Scan - Advanced Controls ................................................................................................................. 18
7.4 Menu Button - Advanced Controls ...................................................................................................19

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Introduction
Congratulations on purchasing the world’s first single-chip Atomic Force Microscope (sc-AFM)
system! nGauge achieves magnification that far surpasses that of an optical microscope, so that you may
explore the world with nanometer-scale resolution.
The most up-to-date instruction manual can always be downloaded from
www.icspicorp.com/resources.
Please read this instruction manual before operating your new instrument to learn how it works,
how to set up and operate the hardware and software, how to prepare samples, and how to visualize
your data. The nGauge team has made every effort to improve the ease-of-use of AFMs, and we
welcome any feedback that may improve your experience.
1.0 Safety and Precautions
The following warnings and precautions should be observed to ensure the safety of the user and
the instrument:
Use only the power supply provided. The driving electronics are designed to accept 7.5Vdc, and
an internal fuse prevents the input current from exceeding 1A.
The stage contains moving parts that could pinch. To avoid minor injury, be aware of the moving
parts.
Avoid disassembling the system. If not done properly, this could result in damage to the
electronics or the mechanical components.
Be extremely careful when handling an AFM chip. They are very fragile and will break if the tip is
touched. AFM chips should be stored in their box with the tip facing DOWN, and removed using
the tweezers provided. If necessary, the AFM chip can be placed on a flat surface with the tip
facing up. The AFM chip can be picked up by hand by the board as long as you are careful to
avoid touching the tip.
The tip, located at the edge of the
board, is extremely fragile.

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AFM chips should be stored with the tip
facing DOWN in the storage box. Use
tweezers to pick them up.
The AFM chip can be placed on a flat
surface with the tip facing up.
The AFM chip can be picked up by hand
as long as you don't touch the tip.
This is a zoomed-in photo of the AFM
chip. The chip is extremely fragile.

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2.0 Overview
2.1 AFM Basics
Unlike optical microscopes that use light and lenses to magnify, or electron microscopes which
use electron beams to generate an image, Atomic Force Microscopes (AFMs) use a very sharp tip to
measure tip-sample interaction forces and generate a 3D reconstruction of a sample surface. The tip is
raster scanned over a 2D area while a controller maintains a constant tip-sample force by adjusting the
tip's Z height. The control effort then represents the height of the features on the sample.
Conventional AFMs typically use a probe comprising a sharp tip on a silicon cantilever. A laser
beam is reflected off the backside of the cantilever onto a 4-quadrant photodetector that measures any
small displacements of the cantilever. A piezoelectric Z-scanner controls the height of the probe while a
piezoelectric XY stage raster scans the sample in X and Y.
2.2 sc-AFM Basics
A single-chip AFM (sc-AFM) operates in almost exactly the same manner as a conventional AFM
except that all of the essential components are integrated onto a chip. The chip is a
MicroElectroMechanical Systems (MEMS) device that uses the most advanced manufacturing process in
the world to produce tiny, ultra-precise scanners and sensors on a ~1x1mm silicon chip.
An sc-AFM has a cantilever and a sharp tip, but instead of a laser it has an integrated
piezoresistive strain sensor to measure tip displacements. The tip and sensor are attached to a MEMS
scanner that can position them in X, Y, and Z with sub-nanometer resolution.

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2.3 nGauge AFM Components
The nGauge AFM system includes all of the following components. A computer (not included)
with a USB port is required.
1. Stage
2. Sample Platform
3. Thumb Nut
4. AFM Chips
5. Power Supply
6. USB Cable
7. Tweezers
2.4 nGauge AFM Capabilities and Limitations
The nGauge AFM operates in tapping mode, in which the cantilever oscillates at its resonant
frequency and makes intermittent contact, or “taps” the sample surface. It can scan areas of up to
20x20x10um in X, Y, and Z respectively with <1nm RMS Z noise.
Any solid sample can be imaged, including both conductive and non-conductive, but the AFM
cannot operate in liquid and cannot image liquid samples. Some samples, particularly polymers, may be
difficult to image due to surface charging.
3.0 Setup
3.1 Where to set it up
The nGauge AFM is small, simple, and portable, and can be set up just about anywhere.
However, for best results, it is recommended that you adhere to the following guidelines:
Flat surface: The system should be set up on a flat, level surface, like a desk or tabletop, with
enough space to ensure that the stage does not get bumped or moved while imaging.
Vibrations: The unique design of the nGauge AFM minimizes the effects of common sources of
vibrations, such as those caused by people walking by, doors opening and closing, and building
vibrations. However, it is best to set the system up on a solid, stable surface away from as many
sources of vibration as possible.
Air Drafts: The system is not immune to air drafts and should be set up away from air vents,
drafty windows, etc. If air drafts are unavoidable and present a significant problem, a box or
enclosure around the system may be required.

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Electrical Noise: The system meets the FCC guidelines for electrical interference, but it is best to
avoid setting it up near sources of electrical noise, such as server rooms or rooms operating
high-power equipment.
3.2 How to set it up
Setup of the nGauge AFM is very simple.
1. Remove the
components from the
carrying case. Set the
stage upright on a flat
surface.
2. Plug the power supply
into a wall outlet and
into the power
connector in the
stage.

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3. Connect the USB
cable to a computer
and to the USB
connector in the
stage.
4. Completely unscrew
and remove the
thumb nut from the
stage

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5. Open up the AFM chip
box and pick up an
AFM chip using the
tweezers
6. Carefully place the
AFM chip onto the
alignment pins on the
stage with the tip
facing down. During
this step, the sample
platform should be
retracted sufficiently
to avoid any contact
between the tip and
platform.
7. Replace the thumb
nut and firmly tighten
it.
3.3 Installing the Software
The software required to operate the AFM can be found on the USB stick provided, or
downloaded from www.icspicorp.com/resources. To install the software for windows, run the
executable installer “nGauge_setup_x.x.x.x_windows.exe”. To install the software on Mac OS, simply
mount the disk image “nGauge_setup_x.x.x.x_mac.dmg” and drag the nGauge application into the
applications folder.

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If network connection is available, the software will automatically check for updates from the
ICSPI server. This information is displayed on both the home screen and in the updates section of the
menu. To manually query the ICSPI update server for new updates, click Check Updates under the
updates section of the menu.
The open source AFM post-processing software called Gwyddion is a very useful tool and should
also be installed. You can download it from the Gwyddion website: http://gwyddion.net/download.php.
See section 5.1 Gwyddion for more details.
4.0 Basic Operation
4.1 Software Overview
Launch the software by double-clicking on the nGauge program on your desktop or searching for
nGauge in the start menu. If the AFM is powered up and connected to the computer with the USB cable,
the splash screen should display the message "AFM Ready". If not, refer to section 6.0 Troubleshooting.
The setup and imaging workflow is divided into three ordered tabs: Sweep, Approach, and Scan.
To navigate between the three tabs, click on the desired tab in the progress bar at the top of the page.
The menu button at top-right of the page brings out a detailed settings menu for all aspects of AFM
configuration. The settings in this menu are not required for normal operation and most users will never
need to use these controls. Please review section
7.4 Menu Button - Advanced Controls for details.