Category Technology/Electronics

This is an image of the change in luminescence colors of MCL materials. Credit: Youhei Takeda

Mechanochromic luminescent (MCL) materials change their color in response to a change in their environment, like pressure and temperature. To date, most MCL materials only change between 2 colors, limiting their applications. The international research team comprising of chemists at Osaka University and physicists at Durham University has developed tricolor-changing MLC materials. Not only that, the developed materials exhibited efficient thermally activated delayed fluorescence (TADF) and allowed high performance organic light-emitting diodes (OLEDs) devices.

“Most MCL materials generate 2 colors by switching between a stable state and one metastable state...

Photoluminescent compounds synthesized by the Coordination Chemistry and Catalysis Unit glowing under a UV light. Credit: Image courtesy of Okinawa Institute of Science and Technology Graduate University – OIST

Chemical compounds that emit light are used in a variety of different materials, from glow-in-the-dark children’s toys to LED lights to light-emitting sensors. As the demand for these compounds increases, finding new efficient methods for their production is essential. New research describes a new strategy for producing photoluminescent (PL) compounds with increased capabilities.

Production of PL compounds is typically centered around 2 main methods: the conventional metal-ligand system or an aggregation based system...

1. Metamaterial bricks are assembled into a layer to produce a meta-surface, which could have applications across healthcare and entertainment
2, These space coiling bricks act to slow down sound waves, meaning that they can be transformed into any required sound field.

A super-material that bends, shapes and focuses sound waves that pass through it has been invented by scientists. Metamaterials have already shown remarkable results with light manipulation, allowing scientists to create a real-life version of Harry Potter’s invisibility cloak, for example. But a Universities of Sussex and Bristol team have now shown that they also work with sound waves, which could transform medical imaging and personal audio.

Finely shaped sound fields are used in medical imaging and therapy as well as in ...

The buckling-induced cubic patterned kirigami sheet can be folded flat (Image courtesy of Ahmad Rafsanjani/Harvard SEAS)

Origami-inspired materials use folds in materials to embed powerful functionality. However, all that folding can be pretty labor intensive. Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are drawing material inspiration from another ancient Japanese paper craft—kirigami. Kirigami relies on cuts, rather than folds, to change the structure and function of materials.

In a new paper published in Physical Review Letters, SEAS researchers demonstrate how a thin, perforated sheet can be transformed into a foldable 3D structure by simply stretching the cut material...