Lattice defects are ubiquitous in two-dimensional materials (graphene and related twodimensional materials) and play a significant role in their electronic, optoelectronic, thermal, surface, and structural properties of. These defects are present in many form such as vacancies, dislocations, grain boundaries, dopants, and adsorbates, and must be minimized for achieving the best electrical, thermal, and structural properties. Conversely, lattice defects can be beneficial for controlling hole/electron doping, optoelectronic and sensing properties, as well as surface reactions. Over the past decade, several methods have been demonstrated for the introduction of defects in two-dimensional materials; however, these methods do not offer precision control and thus can readily cause adverse effects. For example, polymer-based lithography, which is traditionally used to pattern graphene has been found to significantly reduce its device performance. Solutions to mitigate this include grain boundary engineering to control field-effect mobility and van der Waals encapsulation by hexagonal boron nitride. However, in all of these cases, lithographic techniques limit the feature sizes to ~10 nm due to the use of photoresist and limits imposed by the energy of the electromagnetic radiation.