Atomic Force Microscopy

The instrument uses the cantilever response to extract different kinds of information from the same nanoscale scan. Spatial changes in tip-surface interaction produce a map of surface topography, while the response to applied force supports a map of mechanical properties. Comparing these outputs can reveal whether a visible structural feature also has a distinct mechanical signature.

The cantilever provides a flexible mechanical element that responds to forces acting between the sharp tip and the sample. A laser detects the resulting cantilever deflection, converting a small physical response into a measurable signal during raster scanning. This linkage allows AFM to translate tip-surface interactions into nanoscale images or force maps without requiring labels.

Molecular binding can change the interactions between the probe and the biological surface, whereas applied force can expose how that surface responds mechanically. Consequently, AFM measurements may show differences in force behavior alongside structural features. This makes the technique useful for examining interactions and mechanical changes rather than treating biological surfaces as purely static shapes.

A sharp tip attached to a flexible cantilever is positioned over the specimen, and the tip raster-scans across its surface. Forces encountered during scanning bend the cantilever, while a laser records that deflection. The resulting signal is processed into either a nanoscale surface image or a force map, depending on the measurement objective.

Controlled liquid conditions allow biological specimens to be examined in an environment suited to measurements of cells, membranes, and proteins. Because AFM can operate without labeling or vacuum, researchers can investigate living or fixed specimens while preserving access to surface structure and mechanical behavior. This expands observations beyond approaches that require extensive preparation or labeling.

AFM supports studies of membranes, cells, proteins, nucleic acids, and biomaterials at nanoscale resolution. In biology, measurements can contribute to investigations of cell mechanics, adhesion, and disease-related changes. For biomaterials, maps of structure and mechanical properties can inform design efforts by showing how a material’s surface features and force response are related.