Instruments Available
Atomic Force Microscopy (AFM) is a surface characterization tool that can provide topographic images and quantitative information in both lateral and vertical dimensions. An topographical image is generated when a cantilever with a sharp tip is scanned across the sample surface and the deflection or amplitude of the cantilever is monitored using a laser beam on the back of the cantilever. In addition to topgraphical information, AFM can provide mechanical properties information, including elastic modulus and adhesion.
Key attributes
- High resolution imaging: lateral resolution 1 nm (depending on tip), vertical resolution 0.1 nm
- Samples can be imaged in both air and fluid environments
Strengths
- Samples do not need to be coated or placed in vacuum
- High spatial resolution
- Quantitative measurements in x, y and z
- Allows imaging of biological in real time and in physiological conditions
Limitations
- Scan range limits: 90µm laterally (xy) and 5µm vertically (z) for the Multimode and 150µm laterally (xy) and 20µm vertically (z) for the Catalyst
- Potential problems with extremely rough or oddly shaped samples
- Imaging can cause damage to sample
- Many electrical and magnetic modes are limited to qualitative or semi-quantitative measurements
Applications
- Assessing the surface roughness of thin films before and after processing
- Measuring the adhesion between the tip and sample surface
- Measuring step heights
- Measuring or mapping the mechanical properties of biological materials such as cells or tissues
- Visualizing changes to a sample (i.e. crystal growth) in real time
Additional Reading
