Haptic Sensation-Based Scanning Probe Microscopy: Exploring Perceived Forces for Optimal Intuition-Driven Control

We demonstrate a cryogenic scanned 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 we simulate, by using different SPM modalities, a sensation that is representative of the relevant atomic forces 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 and amplitude 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 Leonard-Jones potential. This manner of SPM control creates new opportunities for human-based intuition scanning, and it also acts as a novel educational tool to aid in understanding materials at an atomic level.