AFM Modes

Torsional Resonance Tunneling AFM (TR-TUNA)

TUNA conductivity mapping capabilities on delicate samples

Soft or otherwise delicate conductive samples can sometimes be damaged when imaging in traditional Tunneling AFM (TUNA) mode. Torsional Resonance (TR) TUNA is an enhanced option that allows TUNA to be used on fragile samples by operating Torsional Resonance (TR) Mode in place of Contact Mode. This modification greatly reduces vertical and lateral tip forces on samples while keeping the tip in the near field where the TUNA currents can be measured—a capability especially important for polymer, thin film, and nanoelectronics applications.

Conductivity data from fragile samples can also be accessed with the PeakForce TUNA™ module, which pairs TUNA conductivity imaging with Bruker’s revolutionary PeakForce Tapping® mode.


Simultaneous topography and conductivity mapping of single-wall carbon nanotubes loosely attached on Au-patterned silicon using TR-TUNA.