  Interfaces of van der Waals (vdW) materials such as graphite and hexagonal
boron nitride (hBN) exhibit low-friction sliding due to their atomically-flat
surfaces and weak vdW bonding. We demonstrate that microfabricated gold also
slides with low friction on hBN. This enables the arbitrary post-fabrication
repositioning of device features both at ambient conditions as well as in-situ
to a measurement cryostat. We demonstrate mechanically-reconfigurable vdW
devices where device geometry and position are continuously-tunable parameters.
By fabricating slidable top gates on a graphene-hBN device, we produce a
mechanically-tunable quantum point contact where electron confinement and
edge-state coupling can be continuously modified. Moreover, we combine in-situ
sliding with simultaneous electronic measurements to create new types of
scanning probe experiments, where gate electrodes and even entire vdW
heterostructures devices can be spatially scanned by sliding across a target.
