Shape-morphing living composites
In a recent study published on Science Advances, L. K. Rivera-Tarazona and a research team in the departments of bioengineering and biological sciences at the University of Texas, Dallas, U.S., established a new method to explore genetic networks in the lab. They created living synthetic composites that changed shape in response to specific biochemical and physical stimuli. For example, Baker's yeast embedded in hydrogel can create a response material where cell proliferation (cell growth) caused controlled increase in the composite volume up to 400 percent. Genetic manipulation of the yeast permitted composites whose volume changed on exposure to L-histidine at a 14-fold higher rate than when exposed to D-histidine or other amino acids. The research team encoded an optogenetic (light responsive) switch in the yeast to control shape changes in space and time, with pulses of dim blue light at 2.7 mW/cm2. The living shape-changing materials can act as sensors...