  Dark matter detectors with directional sensitivity have the capability to
distinguish dark matter induced nuclear recoils from isotropic backgrounds,
thus providing a smoking gun signature for dark matter in the Galactic halo.
Motivated by recent progress in graphene and two-dimensional materials
research, we propose a novel class of directional dark matter detectors
utilizing graphene-based van der Waals heterostructures. A conceptual design of
the detector based on graphene/hexagonal boron nitride and graphene/molybdenum
disulfide heterostructures is developed and analyzed. The proposed detector has
modular scalability, keV-scale detection threshold, nanometer position
resolution, sensitivity down to 10 $\mathrm{GeV}/c^2$ dark matter mass, and
intrinsic head-tail discrimination and background rejection capabilities.
