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Atomic Force Microscopy (AFM)

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What is AFM?

Atomic Force Microscopy (AFM) is a powerful imaging technology used to visualize surfaces at the atomic or nanoscale level. Unlike traditional light microscopes, AFM doesn’t use lenses or light it uses a sharp mechanical probe to “feel” the surface of a sample and create a detailed 3D image.

AFM is widely used in biology, nanotechnology, and materials science to study:

  • Cells and tissues
  • DNA and proteins
  • Nanomaterials and surfaces

🔬 How Does It Work?

AFM uses a tiny, sharp tip attached to a flexible cantilever. This tip gently touches the surface of the sample. As the tip moves across the surface, it goes up and down depending on the texture of the sample.

A laser beam reflects off the cantilever into a detector. As the cantilever bends, the laser moves. This movement is recorded to create a high-resolution 3D image of the surface.

⚙️ Main Modes of AFM

  1. Contact Mode
    The tip stays in direct contact with the surface. Good for hard samples, but may damage soft materials.
  2. Tapping Mode
    The tip lightly taps the surface as it scans. Ideal for delicate biological samples like cells or proteins.
  3. Non-Contact Mode
    The tip hovers just above the surface. This reduces sample damage and is useful for imaging very soft or sticky materials.

🧬 Applications in Biology and Nanotechnology

  • 🧫 Imaging Cells and Bacteria
    View living cells, bacterial walls, and viruses in high detail.
  • 🧬 Studying DNA and Proteins
    Measure the shape, size, and binding of biomolecules.
  • 🔍 Measuring Forces
    AFM can measure how strongly two molecules stick together.
  • 💎 Nanomaterials
    Observe nanoscale textures of polymers, graphene, and other materials.