Category Technology/Electronics

The Structure and Rechargeability of a Room-Temperature Li-N2 Battery
(A) Structure of a Li-N2 battery with a Li-foil anode, ether-based electrolyte, and CC cathode.
(B) N2 fixation (blue) and N2 evolution (red) curves of a Li-N2 battery with a CC cathode at a current density of 0.05 mA cm−2.
(C) CV curves of a Li-N2 battery at a scan rate of 0.05 mV s−1 in N2-saturated (black) and Ar-saturated (red) atmospheres.
(D) Cyclic performance of a Li-N2 battery at a current density of 0.05 mA cm−2.

As the most abundant gas in Earth’s atmosphere, nitrogen has been an attractive option as a source of renewable energy...

This is the water harvester built at MIT with MOFs from UC Berkeley. Using only sunlight, the harvester can pull liters of water from low-humidity air over a 12-hour period. Credit: MIT photo from laboratory of Evelyn Wang

Metal-organic framework sucks up water from air with humidity as low as 20%. Imagine a future in which every home has a solar appliance that pulls all the water the household needs out of the air, even in desert climates. That future may be around the corner, with the demonstration this week of a water harvester that uses only ambient sunlight to pull liters of water out of the air each day with very low humidity. The solar-powered harvester was constructed at MIT using a special material – a metal-organic framework, or MOF – produced at UC, Berkeley.

Omar Yaghi, scienti...

High-Flying Experiments Demonstrate Potential of Balloon-Borne Infrasound Detection

Experiments conducted high in the skies over New Mexico suggest that balloon-borne sensors could be useful in detecting the infrasound signals generated by small, extraterrestrial debris entering Earth’s atmosphere, according to a report at the 2017 Seismological Society of America’s (SSA) Annual Meeting. Infrasound, sometimes called low-frequency sound, is sound waves that occur at frequencies lower than the limit of human hearing. Infrasound signals can remain strong as they travel over large distances, making them useful for pinpointing the location and size of events such as nuclear explosions, meteorite strikes, volcanic eruptions and sometimes earthquake ruptures.

Ground sensors can detect these signa...

A lattice created by a multi-material 3-D printer at Georgia Institute of Technology that can permanently expand to eight times its original width after exposure to heat. Credit: Rob Felt

A team of researchers from Georgia Institute of Technology and two other institutions has developed a new 3D printing method to create objects that can permanently transform into a range of different shapes in response to heat. The team, which included researchers from the Singapore University of Technology and Design (SUTD) and Xi’an Jiaotong University in China, created the objects by printing layers of shape memory polymers with each layer designed to respond differently when exposed to heat.

“This new approach significantly simplifies and increases the potential of 4D printing by incorporating the mec...