Category Physics

A new disposable battery that folds like an origami ninja star could power biosensors and other small devices for use in challenging field conditions. Credit: Jonathan Cohen/Binghamton University

A new disposable battery that folds like an origami ninja star could power biosensors and other small devices for use in challenging field conditions. Seokheun “Sean” Choi, assistant professor of computer and electrical engineering at Binghamton University, along with 2 of his students, developed the device, a microbial fuel cell that runs on the bacteria available in a few drops of dirty water.

Choi previously developed a paper-based origami battery. The first design, shaped like a matchbook, stacked 4 modules together. The ninja star version, which measures about 2...

Fig.1: Crystal structure of (Ga,Mn)As. Mn ions substituted for Ga have a magnetic moment, and the magnetic moment of each Mn ion aligns along the same direction when (Ga,Mn)As becomes a ferromagnet. Credit: Seigo Souma

A research group at Tohoku University’s WPI-AIMR has succeeded in finding the origin and the mechanism of ferromagnetism in Mn-doped GaAs. The discovery is significant as it will accelerate the development of the spintronic element. GaAs, like silicon, is a well-known semiconductor commonly used in high-speed electronic devices and laser diodes.

When manganese (Mn) atoms are doped into a GaAs crystal ((Ga,Mn)As), the crystal exhibits characteristics and properties of both the semiconductor and magnet...

This picture shows an OLED with the composite structure of TiO2/graphene/conducting polymer electrode in operation. The OLED exhibits 40.8% of ultrahigh external quantum efficiency (EQE) and 160.3 lm/W of power efficiency. The device prepared on a plastic substrate shown in the right remains intact and operates well even after 1,000 bending cycles at a radius of curvature as small as 2.3 mm. Credit: KAIST

The arrival of a thin, lightweight computer that even rolls up like a piece of paper will not be in the far distant future. Flexible organic light-emitting diodes (OLEDs), built upon a plastic substrate, have received greater attention lately for their use in next-generation displays that can be bent or rolled while still operating...

Researchers at the University of Cambridge have devised a method to produce “Polymer Opals” on an industrial scale. Credit: Nick Saffell/University of Cambridge

This invention opens up applications ranging from smart clothing for people or buildings, to banknote security. Using a new method called Bend-Induced-Oscillatory-Shearing (BIOS), the researchers are now able to produce hundreds of metres of these materials, known as ‘polymer opals’, on a roll-to-roll process. Some of the brightest colours in nature can be found in opal gemstones, butterfly wings and beetles. These materials get their colour not from dyes or pigments, but from the systematically-ordered microstructures.

The team, based at Cambridge’s Cavendish Lab, have been working on methods of artificially recreating this ‘struc...