Ion Effect and Metal-Coordinated Cross-Linking for Multiscale Design of Nereis Jaw Inspired Mechanomutable Materials

MIT scientists have looked at a sea worm called Nereis virens in order to create a changing material, with the ability to be flexible or rigid at convenience. The jaw of this worm has a texture similar to gelatin, but if the environment varies, the material may adopt the hardness of dentin or human bones. Chemical engineer Francisco Martín-Martínez explains, “the jaw of Nereis virens is composed of a protein that contains large amounts of histidine, an amino acid that interacts with the ions of the environment and makes it more or less flexible depending on the environment in which it finds itself.”

The material is “a hydrogel made from a synthesized protein, similar to th...

Rechargeable nickel–3D zinc batteries: An energy-dense, safer alternative to lithium-ion. Science, 2017; 356 (6336): 415 DOI: 10.1126/science.aak9991

US Naval Research Laboratory’s (NRL) Chemistry Division have developed a safer alternative to fire-prone Li-ion batteries, which were recently banned for some applications on Navy ships and other military platforms. Joseph Parker, Jeffrey Long, and Debra Rolison from NRL’s Advanced Electrochemical Materials group are leading an effort to create an entire family of safer, water-based, zinc batteries. They have demonstrated a breakthrough for nickel-zinc (Ni-Zn) batteries in which a 3D Zn “sponge” replaces the powdered zinc anode traditionally used...

This schematic representation illustrates the technique used to probe the small-scale structure of the cosmic web using light from a rare quasar pair.
Credit: J. Onorbe / MPIA

A team of astronomers have made the first measurements of small-scale ripples in this primeval hydrogen gas using rare double quasars. Although the regions of cosmic web they studied lie nearly 11 billion light years away, they were able to measure variations in its structure on scales 100,000 times smaller, comparable to the size of a single galaxy.

Intergalactic gas is so tenuous that it emits no light of its own. Instead astronomers study it indirectly by observing how it selectively absorbs the light coming from faraway sources known as quasars...