Tiny bulges of specialized cells in a mimosa plant (shown) can fold its feathery leaflets together in seconds, then relax — and do it again. Scientists have already worked out the basic chemistry that drives a little mimosa motor, or pulvinus. But new research shows how the structures of the cells help the plant along. One feature that makes plant-muscle cells bloat more efficiently is reinforcement with microscopic fibrils. They work like corsets, keeping cells from bulging out in all directions. Instead, the corset directs much of the swelling along the axis that will fold up the leaf halves. Also, pulvinus cells that need to bulge fast have what look like wrinkles of easily expandable tissue for inrushing water, plus special highly porous zones called pit fields. The pits look as if water could sluice through easily in a tickled-leaf emergency. Cell arrangement itself looks specialized for expanding and shrinking. (📸: Ole_CNX/iStock/Getty Images Plus) #science #plants #plantsofinstagram #mimosaplant #mimosa #chemistry #biology #botany

Look closely at a snowflake, and you’ll observe a one-of-a-kind gossamer lattice, its growth influenced by ambient conditions like temperature and humidity. Turns out, this sort of intricate self-assemblage can also occur in metals, researchers report. In pools of molten gallium, physicist Nicola Gaston and colleagues grew zinc nanostructures with symmetrical, hexagonal crystal frameworks (shown). After mixing zinc into the gallium, the team subjected the alloy to elevated temperatures and different pressures, and then let the mixture cool to room temperature. Gallium’s loose ordering of atoms appeared to coax the crystallizing zinc to bloom into structures resembling natural snowflakes and other shapes, the team found. Figuring out how to craft tiny, complex metal shapes in fewer steps and with less energy could be a boon for manufacturers. (📸: S.A. Idrus-Saidi et al/Science 2022) #science #chemistry #gallium #zinc #snowflake #microscope #crystal #microstructure