Category Physics

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...

VAMPs are shown actuated and cut open in cross section. The cross section shows the inner chambers that collapse when vacuum is applied. Credit: Wyss Institute at Harvard University

To make robots more cooperative and have them perform tasks in close proximity to humans, they must be softer and safer. A new actuator generates movements similar to those of skeletal muscles using vacuum power to automate soft, rubber beams. Like real muscles, the actuators are soft, shock absorbing, and pose no danger to their environment or humans working collaboratively alongside them or the potential future robots equipped with them.

“Functionally, our actuator models the human bicep muscle,” said Whitesides, Director of the Kavli Institute for Bionano Science and Technology at Harvard University...

The quantum thermal transistor consists of three two-level systems, which can be implemented as spins with an up and a down state. Any one of these systems can control the heat current that flows to the other two, resulting in switching their spins. Credit: Joulain et al. ©2016 American Physical Society

Researchers have designed a quantum thermal transistor that can control heat currents, in analogy to the way in which an electronic transistor controls electric current. The thermal transistor could be used in applications that recycle waste heat that has been harvested from power stations and other energy systems...