Molecules/Matter & Energy

Groovy snake bites, buzzy microphones and coiling liquids in this week’s news

Groovy snake bite Snakes don’t need fancy pressurized fangs to inject venom. A groove on the outside of the tooth, which is more common, will do. The secret to this simple but deadly anatomy starts with the surface tension of the thick venom, which oozes out of a gland in the snake’s mouth. This tension allows the venom to stick to the tooth and spread out slowly, fearless scientists in the United States and Germany who milk snakes report. After a snake bites down, the victim’s tissue forms a tube that rapidly draws in the poison in less than a second, as described in an upcoming Physical Review Letters . — Devin Powell Microphone buzz A new microphone is intentionally buggy. The pinhead-sized sensor is as good at detecting the direction of a sound as are the super-sensitive ears of the Ormia ochracea fly that inspired the technology’s design. Sound waves striking the device at an angle cause three trampoline-like membranes to wobble out of synch with each other. A vibrating beam based on the fly’s anatomy connects these membranes and amplifies the pattern, engineers at the University of Maryland in College Park report in the May Journal of the Acoustical Society of America . The Army Research Laboratory, which is working with the Maryland group, hopes the sensor will help microscale robots navigate. — Devin Powell Liquid-solid limbo You can’t tie it in knots, but a stream of shaving cream behaves like solid rope when it coils in a pile, scientists have discovered. Hair gel, however, piles up more like liquid honey. The experiments suggest that when coiling behavior matters, such as when filling jars with flowy foodstuffs or manufacturing using injectable plastics, you have to know whether to treat in-between materials as solids or liquids, researchers from Iran, the Netherlands and France report in an upcoming Physical Review E . If the material is more like a liquid, determining flowiness will predict coiling behavior; if it’s more like a solid, coiling is dictated by how the material deforms under stress. — Rachel Ehrenberg

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