Fast AFM probes measure multiple properties of biomolecules or materials simu...(material and how stiff and sticky it is....)

An output signal is generated only when there is an interaction force on the probe. In other words, transient interaction forces can be measured during each tap of the tip with high resolution and without any background signal.

In the February 27 issue of the journal Nanotechnology, the researchers described using the FIRAT probe to characterize the elasticity, surface energy and adhesion hysteresis of three polymers and a silicon sample. The quantitative results were mapped in addition to topography.

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.

In collaboration with Cheng Zhu, Regents Professor in the Wallace H. Coulter Department of Biomedical Engineering, Degertekin is using the probe to measure the force between two interacting biological molecules and unbinding forces between two molecules.

By testing different molecules and buffer solutions, researchers can determine the probability of molecule adhesion, a process that requires many repetitive measurements. This has implications in drug discovery, where determining how frequently certain soft biological molecules adhere to each other is important.

Rather than moving a single cantilever up and down a thousand times, we have developed a membrane that would allow parallel measurements of molecules to get thousands of measurements at one time, said Degertekin.

This new technique was described in the February 2007 issue of the journal Nanotechnology. For different applications, Degertekin can adjust the stiffness of the membranes.

The best mechanical measurements of surfaces or
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