Nanomechanical Mapping

PeakForce QNM (Quantitative NanoMechanics), an extension of Peak Force Tapping Mode™, enables quantitative measurement of nano-scale material properties such as modulus, adhesion, deformation and dissipation. Because Peak Force Tapping Mode controls the force applied to the sample by the tip, sample deformation depths are small and the effect of the substrate on the measured modulus is decreased.

PeakForce QNM can provide compositional mapping of a complex composite material while providing equal or higher resolution than a TappingMode image (~5nm). Peak Force Tapping Mode has high spatial resolution, relatively high speed, and can detect a large range of elasticities. PeakForce Tapping mode produces similar results to HarmoniX (see the HarmoniX User Guide, Bruker p/n 004-1024-000 for details) but is much easier to use and covers a wider modulus and adhesion range.

With a calibrated cantilever, Peak Force QNM is quantitative and has high spatial resolution.

Peak Force Tapping Mode™ microscopy, the core technology behind PeakForce QNM and ScanAsyst™, is a new, Bruker-proprietary, primary Atomic Force Microscopy (AFM) mode. Other primary AFM modes include Contact, Tapping, Scanning Tunneling Microscopy (STM) and Torsional Resonance modes.

Peak Force Tapping mode oscillates, but far below the cantilever resonant frequency, the vertical motion of the cantilever using the (main) Z piezo element and relies on peak force for feedback. Peak interaction force and nanoscale material property information is collected for each individual tap.

Because Peak Force Tapping mode does not resonate the cantilever, cantilever tuning is not required. This is particularly advantageous in fluids.

Peak Force Tapping Mode includes auto-optimization (called ScanAsyst) of scanning parameters, including gains, setpoint and scan rate. This enables users to rapidly obtain high quality images. ScanAsyst is intended to be the first choice imaging mode for NanoScope version 8.10 and later software.

Because Peak Force Tapping mode controls the applied force, tip wear is reduced.

Peak Force Tapping mode imaging increases the resolution by controlling the force that the tip applies to the sample thereby decreasing the deformation depths; this decreases the contact area between the tip and sample. Because the deformation depths and lateral forces are small, there is minimal damage to the probe or sample.

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