Scientists out of Georgia Tech have invented novel highly sensitive atomic force microscopy (AFM) technology that is capable of imaging 100 times faster than current AFM:
This technology could prove invaluable for many types of nano-research, in particular for measuring microelectronic devices and observing fast biological interactions on the molecular scale, even translating into movies of molecular interactions in real time…
Not only is FIRAT™ (Force sensing Integrated Readout and Active Tip) much faster than AFM (the current workhorse of nanotech), it can capture other measurements never before possible with AFM, including material property imaging and parallel molecular assays for drug screening and discovery…
Current AFM scans surfaces with a thin cantilever with a sharp tip at the end. An optical beam is bounced off the cantilever tip to measure the deflection of the cantilever as the sharp tip moves over the surface and interacts with the material being analyzed.
FIRAT works a bit like a cross between a pogo stick and a microphone. In one version of the probe, the membrane with a sharp tip moves toward the sample and just before it touches, it is pulled by attractive forces. Much like a microphone diaphragm picks up sound vibrations, the FIRAT membrane starts taking sensory readings well before it touches the sample.
And when the tip hits the surface, the elasticity and stiffness of the surface determines how hard the material pushes back against the tip. So rather than just capturing a topography scan of the sample, FIRAT can pick up a wide variety of other material properties.
“From just one scan, we can get topography, adhesion, stiffness, elasticity, viscosity – pretty much everything,” Degertekin said [Dr. Levent Degertekin, head of the project and an asscoiate professor in the Woodruff School of Mechanical Engineering at Georgia Tech -ed.]
For a regular AFM to detect the features of the object, the actuator must be large enough to move the cantilever up and down. The inertia of this large actuator limits the scanning speed of the current AFM. But FIRAT solves this problem by combining the actuator and the probe in a structure smaller than the size of a head of a pin. With this improvement, FIRAT can move over sample topography in a fraction of the time it takes AFM to scan the same area.
Image caption: FIRAT simultaneously captures a variety of material properties from just one touch, including (from upper left to right) topography, adhesion energy, contact time and stiffness.
The press release…
