CoreAFM — The essence of Atomic Force Microscopy

Overview

CoreAFM — The best value research AFM

Research AFM with a competitive price tag
Integrated system with small footprint
33 modes and functions
Easy handling

The CoreAFM is the result of intelligently combining the core components of AFM to achieve maximum versatility and user-friendliness. Due to this fundamental design approach, the CoreAFM is equipped to perform AFM at its best.

The fusion of a modern flexure-guided scanner, XYZ sample stage, camera, active vibration isolation table, and airflow shielding in a single all-in-one unit results in a complete AFM system with an unparalleled compact footprint. The system comes with a fully digital 24-bit controller developed specifically for the CoreAFM scanhead. All the essential functions of modern AFM are integral components of the CoreAFM system; all you need to do to take the CoreAFM into operation is connect the controller, and plug in power and USB.

Download the CoreAFM Brochure

Get a printable PDF of the CoreAFM brochure.

Dr. Joshua D. McGraw
Gulliver UMR 7083, CNRS
ESPCI-PSL / IPGG
France

In my lab at ESPCI, we study the interfacial dynamics of soft materials. Usually, a polymeric material makes up either the surrounding fluid or a surface layer and a colloid can be used as a tracer or model object interacting with the surface. As such, AFM in general, and colloidal probe AFM in diverse environments more specifically, is a necessity for my lab. With such applications in mind, and with a young researcher’s budget, Marco from Nanosurf’s technical sales team suggested the CoreAFM.

In addition to performing very well in air for surface topographic characterization, the instrument also performs under liquid environments and at elevated temperatures using a colloidal probe. This latter functionality is possible thanks to theCoreAFM’s impressive modularity. An extensive library of accessories and functional add-ons, all with a good value for money, give me the flexibility to upgrade the instrument to suit my research needs as they arise. Lastly, the technical team at Nanosurf is very available for troubleshooting support when the need arises, and have always helped to solve problems efficiently. Given the instrument’s value-for-money, the personal and efficient technical support, the instrument’s performance and modularity, I would not hesitate to recommend the CoreAFM.

Seamlessly extendable functionality

Thirty-two standard and optional modes with fully compatible add-ons make the CoreAFM the tool of choice for applications ranging from materials research to life science and electrochemistry. Starting from the basic CoreAFM system, its functionality can be seamlessly extended. Advanced AFM modes and functionality like sample heating, environmental control, scripting, and many others can easily be added to your CoreAFM. For details and dependencies, see the overview graphic.

Easy setup and handling

See for yourself how easy it is to prepare and operate the CoreAFM. Watch the video for a demonstration of the main features, and a brief tutorial on how to perform a measurement using this system.

Spike-Guard

Deeper system integration of the Isostage is reflected in the unique Spike-Guard, which eliminates glitches during imaging. Although the Isostage is an active vibration isolation system, glitches can still occur when distortions are too severe. Spike-Guard detects such anomalies and rescans the line for a distortion-free image.

Powerful and versatile

State of the art electronics with 24-bit ADC and DAC ensure high-resolution XYZ driving of the 100×100×12 µm scanner and allow for low-noise force detection limited only by the cantilever. Thirty-two standard and optional modes with fully compatible add-ons make the CoreAFM the tool of choice for applications ranging from materials research to life science and electrochemistry. Starting from the basic CoreAFM system, its functionality can be seamlessly extended.

A closed scanner compartment features acoustic and air current isolation, while sample stage positioners still allow you to adjust your sample

When the scanner compartment is opened, it provides access to the scanner and sample stage, e.g. to place a new sample for measurement

CoreAFM imaging modes

This overview shows which modes the instrument is capable of. Some modes may require additional components or software options. For details, please view the brochure or contact us directly.

Standard imaging modes

Static Force Mode

Lateral Force Mode

Dynamic Force Mode (Tapping Mode)

Phase Imaging Mode

Magnetic properties

Magnetic Force Microscopy

Electrical properties

Conductive AFM (C-AFM)

Piezoelectric Force Microscopy (PFM)

Electrostatic Force Microscopy (EFM)

Kelvin Probe Force Microscopy (KPFM)

Mechanical properties

Force Spectroscopy

Force Modulation

Stiffness and Modulus

Adhesion

Unfolding and Stretching

Force Mapping

Lithography and Nanomanipulation

Electrochemical AFM (EC-AFM)

Included measurement modes

The CoreAFM can perform static force, dynamic force, phase imaging, MFM, lateral force, force modulation, standard spectroscopy, and standard lithography out of the box. You can however enhance your measurement experience with CoreAFM mode kits.

Included standard mode kits

By default, the CoreAFM comes with the static force mode kit, dynamic force mode kit, and phase imaging mode kit to get you started right away. Depending on the measurement mode, a mode kit may include samples, suitable cantilevers, accessories, or a combination thereof.

Additional standard mode kits

Additional standard-level mode kits that can be acquired separately are the standard spectroscopy kit, standard lithography kit, standard MFM mode kit, standard liquid mode kit, lateral force mode kit, and force modulation mode kit.

System dimensions

Applications

CoreAFM application examples

Kelvin probe force microscopy (KPFM) on graphene

Graphene belongs to the category of 2D materials and is of interest in the research and development of new devices and materials. Besides atomic resolution imaging of graphene to learn more about crystal orientation, edges and defects, the functional properties of graphene are also of great interest.

In this application note, multilayer graphene was imaged with Kelvin probe force microscopy (KPFM) using a CoreAFM to study the contact potential difference variation on a single flake.

Optical image recorded on an upright microscope with a 50x NA0.9 objective. Inset: area where KPFM data and AFM images of graphene were recorded

Topview image of same area in CoreAFM

Multilayer graphene flakes were generated by mechanical exfoliation of graphite and subsequent transfer to a silicon-silicondioxide substrate. The KPFM measurement was carried out in single-run mode, recording the contact potential during the scanning of the topography.

Thin flakes were localized on the substrate with an upright microscope. Using markers on the substrate, the same flakes were placed under the cantilever using the topview camera of the CoreAFM, after which AFM images of graphene and KPFM data were recorded.

Overlay of contact potential difference on an AFM topography image of a multilayer graphene flake.

Sample courtesy: Hiske Overweg, Klaus Ensslin, ETH Zürich, Switzerland

All measurements were performed using a CoreAFM system equipped with a PPP-EFMR cantilever from Nanosensors. AFM images of graphene were processed using the MountainsMap SPM.

Out of plane piezoresponse force microscopy (PFM) on Lithium Niobate

Lithium Niobite (LiNbO₃) is an optically transparent, piezo responsive material used, for example, in piezo sensors or in mobile phones. We tested a LiNbO₃ sample (PFM03, obtained from TipsNano, Estonia) with CoreAFM. The sample has a regular domain structure with 10-µm period. The spontaneous polarization has the opposite direction in the neighboring domains.

To measure the piezoresponse during imaging, a 7.5 V AC voltage was applied to the cantilever while raster scanning the tip over the sample. In response to the applied voltage, the sample periodically expands and shrinks, either in phase with or in counter phase to the excitation frequency. Despite a small measured RMS roughness of 0.3 nm, the domains could not be recognized in the topography. The domains could however be readily identified in the out of plane piezoresponse.

3D representation of phase in color overlaid on topography of PFM03 showing domains with different phase. Image size: 20 µm

CoreAFM image gallery

Twisted graphene layers

Magnetic force microscopy of thin permalloy film with stripe domains

Topography of SrTiO3 in dynamic mode

Magnetic force microscopy of digital backup tape

Topography on multilayer graphene

KPFM on multilayer graphene

Topography of MoS2 monolayer

MoS2 monolayer: 3D topography overlaid with KPFM signal

Topography of locally deposited charges on an insulating oxide surface

KPFM of locally deposited charges on an insulating oxide surface

Topography of an integrated circuit structure with multiple transistor contacts

Conductive AFM of an integrated circuit structure with multiple transistor contacts

Out of plane PFM on Lithium Niobate

Electrostatic force (EFM) measurements on aluminum dots deposited on gold

Topography of polished stainless steel

KPFM on polished stainless steel

DIMO

Digital Inverted Microscope Options

	View samples from below
	Exchangeable objective lens
	Enhances FluidFM^® functionality

The CoreAFM is a very versatile atomic force microscope that can be used for a multitude of different types of research. The digital inverted microscope option (DIMO) enhances your CoreAFM to allow optical view from below, replacing the need for a completely different AFM setup with an inverted microscope.

Enhanced viewing ability

The DIMO empowers you to conduct advanced experiments that require an inverted microscope, as is the case for many Bio AFM applications. It enhances your capabilities when using accessories like the petri dish holder (visible at the beginning of the video to the right), and does not obstruct any standard accessories that fit your CoreAFM (with the exception of the variable magnetic field sample holder).

Fluorescence measurements

The DIMO uses the internal illumination source for transmission optical microscopy. With the fluorescence option, light from an optical fiber can be easily guided into the CoreAFM for epi-illumination from the bottom.

AFM data can be overlaid with the optical data to colocalize information from each imaging mode. The image shows an overlay of AFM topography with fluorescence (green) and transmission light (gray) optical microscopy images. The overlay was created with MountainsMap image processing software.

High-powered microscope optics

Objective: 20× 0.4 NA long working distance objective from Nikon
Objective is interchangeable between experiments with other Nikon objectives that have a M25×0.75 thread and 60-mm parfocal length
Camera: Highly sensitive 2.3 MP monochrome CMOS camera with 5.86 µm × 5.86 μm pixel size (eq. 1/1.2”), USB 3.0, frame rate up to 48 frames/s at full size
Fluorescence option with fiber coupling and filter set that can be changed between experiments
Filters are in a Nikon filter block, as used for Eclipse Ti series microscopes
Optical resolution: 0.8 µm with default objective and transmission
Motorized focusing and cantilever centering

0.8μm resolution with 20x 0.4 NA objective shown on USAF 1951 Resolving Power Test Target

0.8 μm resolution with 20× 0.4 NA objective shown on USAF 1951 Resolving Power Test Target

FluidFM®

FluidFM®: The established microfluidic tool for single-cell biology and nanomanipulation

FluidFM literally brings microfluidics to the tip of an AFM cantilever. This way, it combines the microfluidics with the force sensitivity and positional accuracy of an AFM allowing a range of exciting applications in single-cell biology and nanoscience.

Nanosurf has a long experience providing AFM systems with FluidFM having launched the FlexAFM with FluidFM in 2011 together with Cytosurge. This integration of FluidFM on Nanosurf platforms has grown over time and now the FluidFM technology is available for Nanosurf's FlexAFM, CoreAFM and of course the flagship DriveAFM platform.

FluidFM^® on the CoreAFM using DIMO

Nanosurf has a long-standing collaboration with Cytosurge and has been developing FluidFM^® solutions for FlexAFM since 2011, offering powerful applications for single-cell analysis and manipulation.

The DIMO upgrades the CoreAFM to be capable of performing FluidFM^® on biological samples too.

Below is an example of FluidFM^® colloidal spectroscopy on HeLa cells: the powerful digital microscope allows you to easily view cells, maneuver the cantilever, and carry out your single-cell manipulations.

(Left) Optical image of cantilever with attached colloid taken with DIMO. (Right) Elastic modulus of HeLa cell measured with FluidFM® colloidal spectroscopy

Motorized function for cantilever centering and focus

FluidFM® spotting observed by DIMO

Single cell injection with FluidFM

SMM

Scanning Microwave Microscopy (SMM)

Key benefits

Electrical characterization of materials – dielectrics, semiconductors and metals
High sensitivity to changes of dopant density in semiconductors
High sensitivity to DC capacitance
Minimal sample preparation
Imaging of buried structures

SMM technique

Scanning microwave microscopy (SMM) is a scanning probe technique, that measures the interactions of a microwave from a sharp tip with the sample. The microwave reflection coefficient (S11 parameter), which is the ratio between the microwave power sent to the tip and the one received back after being reflected at the tip-sample contact, is used to deduce the local tip-sample microwave impedance. The microwave impedance yields information about the local capacitance from which one can deduce the dielectric constant and the dopant density. In terms of the dopant density measurement, the SMM is similar to the scanning capacitance microscopy (SCM), but offers wider range of measurements. SMM can be used for measurements of not only semiconductors, but also dielectric materials and metals, since it is not solely relying of the modulation of the depletion capacitance in the sample.

Nanosurf SMM controller (left), SMM cantilever holders: DriveAFM (top right), FlexAFM (bottom right).

Understanding the S11 Parameter

The S11 parameter is defined as a function of the complex impedances of reference impedance (Z₀) and load (Z_L) – Eq.1. Impedance is a complex value and can be represented as a sum of real and imaginary parts – Eq.2. The real part of Z is resistance (R) and the imaginary part can be considered as capacitance (C) -Eq.3. Depending on the sample, resistance and capacitance are functions of conductivity, dielectric constant and carrier density.

Download the SMM brochure

Hardware

Powerful digital signal processing is analysing signal at 1 MHz, far away in frequency from 1/f noise. The signal is digitized early at the analog front-end and such typical issues of analog systems as DC-offset re-adjustment are absent in this configuration. FPGA software has sideband detection capabilities, and dS/dV (dC/dV) measurement does not require any additional hardware, e.g. lock-in amplifiers. Both S11 and dS/dV signals are digital. High working frequency around 5 GHz means better sensitivity to capacitance.

Block diagram of the Nanosurf SMM electronics.

Software

Nanosurf SMM GUI with system controls (left) and scan window (right). Measurement can be started with as little as 4 clicks.

Application examples

SMM provides ultra-sensitive measurements of local capacitances. A capacitance measurement can yield material or device parameters, and it is indispensable for characterization of semiconductor materials, and electronic structures. Read in more detail about application examples in our SMM technical note and application note on Studies of MC2 capacitance standard sample by scanning microwave microscopy (SMM)

Topography (left), Im(S11) or capacitance (right) of an SRAM sample. Scan size is 25 x 25 μm².

Topography (left), Im(S11) or capacitance (right) of an SRAM sample. Scan size is 10 x 10 μm².

Amplitude of dS/dV (dC/dV) measurement (left), and phase (right) of an SRAM sample. Scan size is 11 x 11 μm².

Topography (left), capacitance map in fF (middle) of an MC2 capacitance standard sample – gold dots on SiO₂ terraces on Si. The dotted line on the capacitance map denotes the area of the cross-section on the right. The smallest capacitance of a dot is 0.3 fF and capacitance steps between terraces are 0.04 fF. Scan size is 52 x 52 μm².

Topography (left), S11 amplitude (middle) and dopant density map (right) of an Infineon SCM calibration sample with dopant densities in a range of 4x10¹⁵ – 10²⁰ cm^-3. Scan size is 50 x 50 μm².

Amplitude of dS/dV (dC/dV) measurement (left), and phase (right) of an Infineon SCM sample. Phase image shows clear difference between doping types: N or P. Scan size is 40 x 40 μm².

Nanosurf SMM Option

The Nanosurf SMM option is currently available for the Nanosurf CoreAFM and FlexAFM and DriveAFM.

Specifications
Power (dBm)	4
Frequency (GHz)	around 5.0
DC noise (aF)	0.5
Doping concentration (1/cm³)	10¹⁵ – 10²⁰
Signal down-conversion	digital
Software integration	yes
Modes	S11, dS11/dV (dC/dV, dR/dV) without external lock-in

Accessories

CoreAFM options and accessories

Standard sample holder

Samples up to 100 mm in diameter, central magnet to hold small samples on pucks, clips to hold larger samples.

Petri dish holder

Holds petri dishes of 35 or 50 mm diameter and height up to 10 mm.

Heater sample holder

Heats samples up to 250 °C. Needs TEC controller CH1.

Cooling & heating sample holder

Temperature range of -35 °C to 180 °C. Needs TEC controller CH1, pump and temperature reference unit.

TEC contoller CH1

Temperature monitoring and control, temperature stability < 0.05 °C.

Pump and temperature control unit

Used with cooling & heating sample holder. Includes a pump and temperature control unit for the circulating coolant.

C-AFM sample holder

Sample holder for advanced conductive AFM option. Current range of ± 25 nA with a sensitivity of 10⁸ V/A. Current noise 1.5 pA at 2 kHz bandwidth.

150 µm z-stage

Z-range extension of up to 150 µm for long range force spectroscopy experiments. For petri dishes of 35 mm diameter and 50 mm diameter.

Variable magnetic field sample holder

Variable in-plane magnetic field, integrated Hall sensor, Max. field – 720 mT (2 mm gap), Field resolution – 0.1 mT, Sample size - up to 10 x 10 mm².

Digital inverted microscope option

The DIMO can be integrated with Isostage 300, SMA optical port for illumination, Motorized centering and focus, Nikon objective, Fluorescence option with a fiber coupled light source.

EC cell

For electrochemical experiments, PEEK or PVDF EC cell in a stainless-steel frame. Built-in electrode and tubing feedthroughs.

Environmental control chamber

For sample measurements under controlled environments. Expanding sealing membrane. Gas inlet and outlet.

AE 350

Acoustic enclosure for the stand-alone setup

Samples & mode kits

Mode Kits

CoreAFM standard conductive AFM mode option
Dynamic force mode kit
EFM mode kit
Force modulation mode kit
Lateral force mode kit
Phase imaging mode kit
Standard liquid mode kit
Standard lithography kit
Standard MFM mode kit
Standard spectroscopy mode kit
Static force mode kit

Cantilever holders

Cantilever holder liquid/air flat
Cantilever holder liquid/air flat conductive
Cantilever holder liquid/air flat grooveless 0.3 mm
Cantilever holder liquid/air flat grooveless 0.6 mm

Software

Control software

The control software for Nanosurf AFMs is an intuitive platform made for performing your AFM measurements efficiently and easily. Our Service team and software engineers are constantly developing and implementing new features and enhancements to further improve the user experience. We regularly publish new and improved versions, which you can download for free. You can install the software on as many computers as you wish to analyze your data.

Free lifetime updates: download all software updates for free

All software updates for Nanosurf control software are free of charge. Our software team is constantly working on new features and improvements to make the user experience better, more intuitive and more efficient.

Software features

Automatic/parameter-free frequency tuning based on cantilever characteristics

Simply choose the cantilever you are using, and the system automatically performs the frequency sweep prior to approaching the sample. No manual setting of parameters is required.

Distance measuring tools: measure the distance between points or lines, the height of features, and more

A selection of different measuring tools allow you to accurately measure angles and distances directly on the acquired measurement image.

Determine the distance between two points or between two parallel lines to make very precise measurement (as shown in the video).

Scripting interface: Python package for COM interface

Python API for data acquisition and control of Nanosurf atomic force microscopes

At Nanosurf we realize that leading researchers are often interested in modifying the standard routines of an instrument, or else everyone would be doing the same thing with the same hardware.

Sometimes there are also application-specific routines, the scope of which we cannot predict and program ourselves. This is why we developed the Nanosurf Scripting Interface.

This interface can be used for automation of routine tasks and for creating new experiments. It gives the users full control over our user interface, and some control over the hardware functionality.

The Nanosurf control software publishes its functionality via the COM interface, by running an instance of COM Automation Server. COM Automation Clients can ask the server during the runtime about its functions and access them. These functions can be accessed through most modern programming languages: Python, C++, C#, VBS, Matlab, JS, LabView, etc.

For ease of use, Nanosurf has created a Python API for its COM interface. We chose Python as our API language, because of its ease of use and learning, popularity and universality, and because of number of data and image processing libraries used in academia and industry.

The Nanosurf Python package can be downloaded and installed from PyPI using pip:

pip install nanosurf

Nanosurf Python Package

See how to take control over the GUI settings in Python. The video shows the most basic actions, like changing the imaging mode, choosing the right cantilever, adjusting image parameters and the PID settings. See how to automatically find the working frequency, start the approach, start scanning, and save the data.

On-demand webinar on Nanosurf's Python API

In this webinar we introduce the Nanosurf Python API and learn how to control Nanosurf instruments with it. We also briefly touch on the processing of the data, stored in NID files, and look at how to create custom user interfaces.

Additional usability features

Spectroscopy wizard: follow easy steps to set up spectroscopy measurements
One software UI for all scan heads: no additional learning curve if you use multiple Nanosurf AFM systems
Automated deflection calibration
UI layouts for beginners and advanced users
Highly configurable graph area with mode-dependent auto-layout: the software automatically shows the relevant graphs and information
Easy file handling with comfort features: auto apply naming conventions, Windows Explorer integration, image gallery, bulk renaming.