Category Chemistry/Nanotechnology

Three types of large-area solar cells made out of two-dimensional perovskites. At left, a room-temperature cast film; upper middle is a sample with the problematic band gap, and at right is the hot-cast sample with the best energy performance. Credit: Los Alamos National Laboratory

In a step that could bring perovskite crystals closer to use in the burgeoning solar power industry, researchers have tweaked their crystal production method and developed a new type of 2D layered perovskite with outstanding stability and more than triple the material’s previous power conversion efficiency.

“Crystal orientation has been a puzzle for more than two decades, and this is the first time we’ve been able to flip the crystal in the actual casting process,” said Hsinhan Tsai, a Rice graduate student at L...

Microscopy of self-oscillation of the crystalline assembly. A crystalline assembly of azobenzene derivative and oleate showed oscillatory bending-unbending motion under continuous 435-nm light irradiation. The frequency of oscillation increased with increasing light intensity. Credit: Copyright Ikegami T. et. al., Angewandte Chemie International Edition, May 19, 2016

Scientists have developed light-powered molecular motors that repetitively bend and unbend, bringing us closer to molecular robots. Researchers are working on mimicking cellular systems to develop molecular motors that can move or even deliver drugs to target tissues. Engineering such motors may ultimately lead to molecular robots that can execute more complex tasks...

Production of ImmuStick: Application of immune receptors onto the test strip. Credit: © Photo Fraunhofer IGB

At present, bacteria, fungi or viruses can generally only be detected with certainty by way of elaborate lab tests or animal experiments. The food and pharmaceutical industries would like to have faster tests to check their products. Fraunhofer researchers are therefore developing a stick that works like a pregnancy test and quickly delivers a result. In the future, it is also to be used for detecting allergens and disease pathogens in the blood.

“The ImmuStick can even detect pathogens outside the body – on medical devices or in hospital rooms for example. However, the technology would certainly also be of interest for testing human blood for germs or allergies,” says Dr...

The MOF used in this study consists of organic molecules (in grey and black) and metal ions (zirconium, in purple). Between these molecules are little holes that can absorb the phosphanates (in yellow). © KU Leuven – Centre for Surface Chemistry & Catalysis

The best-known electronic nose is the breathalyser. As drivers breathe into the device, a chemical sensor measures the amount of alcohol in their breath. This chemical reaction is then converted into an electronic signal, allowing the police officer to read off the result. Alcohol is easy to detect, because the chemical reaction is specific and the concentration of the measured gas is fairly high. But many other gases are complex mixtures of molecules in very low concentrations.

Researchers from KU Leuven have now built a very sensitiv...