Haptic sensation-based scanning probe microscopy: Exploring perceived forces for optimal intuition-driven control

We demonstrate a cryogenic scanning probe microscope (SPM) that has been modified to be controlled with a haptic device, such that the operator can 'feel' the surface of a sample under investigation. This system allows for direct tactile sensation of the atoms in and on top of a crystal, and allows the operator to perceive, by using different SPM modalities, sensations that are representative of the relevant atomic forces and tunneling processes controlling the SPM. In particular, we operate the microscope in modes of (1) conventional STM feedback, (2) energy-dependent electron density imaging, (3) q-plus AFM frequency shift based force sensing, and (4) atomic manipulation/sliding. We also use software to modify the haptic feedback sensation to mimic different interatomic forces, including covalent bonding, Coulomb repulsion, Van der Waals repulsion and a full Lennard-Jones potential. This manner of SPM control creates new opportunities for human-based intuition scanning, and also acts as a novel educational tool to aid in understanding materials at an atomic level.