Researchers at Penn State, the Department of Energy’s Oak Ridge National Laboratory and Lockheed Martin Space Systems Company have developed methods to control defects in two-dimensional materials, such as graphene, that may lead to improved membranes for water desalination, energy storage, sensing or advanced protective coatings.   For a two-dimensional, one-atom-thick material like graphene, defects such as small cracks or holes can make a big difference in performance. Usually, these defect...