Scanning Probe Microscopy Facility

Origin AFM Sample Preparation

Sample preparation will vary depending on the sample, imaging mode, and size of desired images.

You will likely need to do a literature search to find the preparation best for your sample. Smaller images or more complex imaging modes will demand more stringent sample preparation.

General Preparation

Mandatory

  1. The sample must be less than 7 mm in height.
  2. The sample must be securely affixed to a glass slide.

Recommended

  1. Samples should be relatively flat, and have few to no gashes, ridges, or other defects over 1 um in size.
  2. Samples should have no adhesive substances on them.
  3. Samples should be clean.

Liquid Imaging

The full sample preparation will be dependent on the sample.

  1. Substrates: Common substrates for droplet imaging are mica, HOPG (highly oriented pyrolytic graphite), silicon or gold.
  2. Support:
    1. The substrate must be affixed to a glass slide for imaging. 
      1. Epoxy or super glue are recommended.
      2. Carbon tape should also work.
    2. To create a droplet there must be a hydrophobic region surrounding the substrate.
      1. PAP pens are the most convenient.
      2. Teflon (threading) tape
      3. Parafilm
      4. PTFE (polytetrafluoroethylene, or Teflon) printed slides
      5. High vacuum grease
    3. Set up samples in a manner that liquid will stay locked into one area on the substrate (glass slide).
      1. Use parafilm, carbon tape, or other hydrophobic material to isolate a central zone on the slide where liquid/buffer and sample will reside.
      2. Alternatively, use the petri dish setup and fully immerse samples within it with some additional setup.
  3. Sample: The sample will need to be affixed to the substrate. 
  4. Solution: It is best to have the solution at room temperature.

Conductive Imaging

  1. The sample being used must be the proper dimensions for CAFM, Conductive Atomic Force Microscopy. It has to be 1-5 cm in diameter and less than 1 mm thick for optimal results.
  2. Conductive AFM must be done either on dry samples or with non-electrolytic liquids.

Safety Procedures