Credit: Image courtesy of Paul Chaikin, New York University
For materials, a new process achieves self-replication and selective control of evolving properties. Seven million copies were made in just 24 cycles that mimicked the light and temperature pattern of Earth’s days and nights. On the left are schematics with corresponding atomic force microscopy images below. A seed of two rafts labeled “T” has protruding sticky ends (red vertical rods). At “night” during low temperatures, the sticky ends on “A” rafts reversibly assemble on the complementary ends of the “T” seed. At “sunrise,” the ultraviolet light causes the two “A” rafts to bind together. As the temperature rises during the “day,” the bound “A” offspring are released from the parent “T”. On the right, the offspring after several cycles are shown (scale bar is 100 nanometer).