The development of colony biofilms by Pseudomonas aeruginosa is affected by redox-active compounds called phenazines. A phenazine-null mutant forms a hyperwrinkled colony with prominent spokes, while wild-type colonies are more constrained and smooth. —Image courtesy of Hassan Sakhtah, Columbia University
Placing a sheet of atomically-thin graphene into a feedback circuit causes spontaneous self-oscillation that can be tuned to create frequency modulated (FM) signals. —Image courtesy of Changyao Chen, Sunwoo Lee, Columbia University.
