Dimension Icon: Atomic Force Microscope (AFM)

Dimension Icon AFM Instrument Type Microscopy Techniques PeakForce Tapping Mode, Tapping Mode, Contact Mode, Quantitative NanoMechanics, Piezoresponse Force Microscopy, Magnetic Force Microscopy, Electrostatic Force Microscopy Staff Manager Matthew S. Hunt, PhD Staff Email matthew.hunt@caltech.edu Staff Phone 626-395-5994 Reserve time on LabRunr Request training by email Lab Location B203B Steele Lab Phone 626-395-1545 Manufacturer Bruker Model Dimension Icon

Description

An AFM measures a sample's topographic and other surface information by interacting a nanoscale probe with the sample. The Dimension Icon offers three main interaction modes: (1) PeakForce Tapping Mode, which operates in conjunction with Bruker's ScanAsyst® to allow the software to automatically optimize several imaging parameters for high-quality, relatively easily obtained images; with tapping oscillations of 0.25 to 2.0 kHz, it is also capable of capturing a force curve at each pixel in order to facilitate extraction of mechanical property data using the Quantitative NanoMechanics (QNM) software package; (2) Tapping Mode, a more traditional tapping interaction that operates near the probe cantilever's resonant frequency (usually 10s to 100s of kHz) to provide topographic and phase imaging; (3) Contact Mode, for direct, constant contact between the probe and surface, which is necessary for several other surface measurement techniques.

Applications

• Topographic imaging of surface features ranging from sub-nm to several microns in height
• Roughness measurements resulting from sub-nm Z resolution
• Phase imaging to qualitatively identify different phases of material by their surface properties
• Quantitative NanoMechanics (QNM) to extract material property data from force curves (e.g. elastic modulus, adhesion, energy dissipation)
• Piezoresponse Force Microscopy (PFM)
• Magnetic Force Microscopy (MFM) using Lift Mode
• Electrostatic Force Microscopy (EFM) using Lift Mode
• Surface Potential measurements
• Measurements in liquid environments are possible
• See Bruker's Scanning Probe Microscopy Techniques Poster
  • The KNI does not currently have modules for Scanning Tunneling, TUNA & Conductive, Scanning Spreading Resistance, Scanning Capacitance, or Scanning Thermal modes; inquire with the MMRC at Caltech for access to some of these advanced techniques.

Resources

SOPs & Troubleshooting

• PeakForce Tapping & Tapping Mode SOPs (Short Version | Long Version)
• Troubleshooting Guide

Video Tutorials

• Basics of ScanAsyst & PeakForce Tapping Mode (video by Bruker)
• Aligning the Laser (video by Bruker)

Technical Notes

• Introduction to Bruker's ScanAsyst and PeakForce Tapping AFM Technology

Presentations

• Bruker's presentation on Image Quality & PeakForce Tapping
• Bruker's presentation on Quantitative NanoMechanics (QNM)

Manufacturer Manuals

• Bruker Dimension Icon Instruction Manual (Scanning Software)
• Bruker NanoScope Analysis V150 Manual (Analysis Software)

Order Your Own Probes

• Probes are considered consumable items that users users are responsible for investigating and purchasing themselves. ScanAsyst-Air probes are commonly used with PeakForce Tapping Mode for topographic imaging, while the selection of Tapping Mode probes relies on a number of factors related to your sample. See Bruker's "Easy Product Wizard," for example, for some probe selection guidance.

Specifications

Manufacturer Specifications

• Dimension Icon Product Guide & Data Sheet

AFM Specifications

• Minimum Feature Size Resolved, Z: ~0.1 nm
• Minimum Feature Size Resolved, X & Y: ~2 nm
• X & Y scan range: 90 μm x 90 μm
• Z scan range: up to 10 μm
• Z noise floor: <30 pm RMS in appropriate environment (imaging bandwidth up to 625 Hz)
• Z sensor noise level(closed-loop): 35 pm RMS (imaging bandwidth up to 625 Hz); 50 pm RMS force curve bandwidth (0.1 Hz to 5 kHz)
• X & Y position noise (closed-loop): ≤0.15 nm RMS (imaging bandwidth up to 625 Hz)
• X & Y position noise (open-loop): ≤0.10 nm RMS (imaging bandwidth up to 625 Hz)
• Integral nonlinearity (X-Y-Z): <0.5%
• Sample Size: ≤210 mm diameter, ≤15 mm thick
• Motorized position stage (X-Y axis): 180 mm × 150 mm inspectable area; 2 μm repeatability, unidirectional; 3 μm repeatability, bidirectional
• Microscope optics: 5-megapixel digital camera; 180 μm to 1465 μm viewing area; Digital zoom and motorized focus