Faster, more sensitive AFM probes extend nanoscale measurements

April 17, 2008 | Source: KurzweilAI

New Georgia Institute of Technology research demonstrates that novel probe technology based on flexible membranes can replace conventional atomic force microscopy (AFM) cantilevers for applications such as fast topographic imaging, quantitative material characterization and single-molecule mechanics measurements.

The force sensing integrated readout and active tip (FIRAT) probes also simultaneously measure material properties including adhesion, stiffness, elasticity and viscosity.

The new probe replaces the AFM cantilever with a drum-like membrane from which a tip extends to scan the material sample. In one scanning mode, as the tip moves above a surface, it lightly taps the material. With each tap, the instrument gathers precise information about both the tip’s position and the forces acting on it, sensing the shape of the material and how stiff and sticky it is.

FIRAT probes made of dielectric materials with embedded actuation electrodes have also been designed for operation in liquids. The design of these membrane-based probes also makes them relatively easy to arrange in arrays in which each probe can move independently. One application of such an array is fast parallel measurements of forces between biological molecules.

Source: Fast AFM probes measure multiple properties of biomolecules or materials simultaneously