Two-dimensional materials are flexible, transparent, compatible with living systems, and can enable new devices and physics based on their unique properties. One unique property is the ability of 2D crystals a single atom thick to undergo massive amounts of strain without failure. Since strain also drastically modifies the band structure leading to large changes in transport and optical properties, strain engineering of 2D crystals has the potential to create new devices, explore transport in pseudo-magnetic fields, and tune tunneling or excitonic effects.  ...