Category Physics

(a) Schematic demonstration of the system and the lifting process. The force and energy change involved are highlighted). (b) Hierarchical structure of silk fibers. The single silk fiber consists of tiny silk threads.

Spider silk offers new inspiration for artificial muscle technology. The silk of the Ornithoctonus Huwena spider demonstrates impressive weight-lifting abilities with efficient, water-driven actuation. The triggered stretching behavior of muscle is inherently based in geometry, characterized by a decrease in length and increase in volume (or vice versa) in response to a change in local environment, eg humidity or heat.

“Spider silk is a natural biological material with high sensitivity to water, which inspires us to study about the interaction between spider silk and water,” ...

This is the directional emission of light. Credit: TU Wien

Recently, surprising physical effects were observed using special microscopic waveguides for light. Such “photonic structures” currently are revolutionizing the fields of optics and photonics, and have opened up the new research area of “Chiral Quantum Optics.” What one learns at school is that light oscillates under a right angle (transversal) with respect to its direction of propagation. Among experts, however, it was already known that light behaves differently when it is confined strongly in the transversal plane using “photonic structures.” In particular, this is the case for special ultra-thin glass fibers which have a diameter of only a few hundred nanometers and which are thereby smaller than the wavelength of light...

From the top left corner, moving clockwise, the four images depict: University at Buffalo students performing an experiment, clean drinking water, water evaporating, and black carbon wrapped around plastic in water with evaporated vapor on top evaporated water. Credit: University at Buffalo.

You’ve seen Bear Grylls turn foul water into drinking water with little more than sunlight and plastic. Now, academics have added a third element—carbon-dipped paper—that may turn this survival tactic into a highly efficient and inexpensive way to turn saltwater and contaminated water into potable water. The idea could help address global drinking water shortages, especially in developing areas and regions affected by natural disasters.

“Using extremely low-cost materials, we have been able to crea...

Fabian Zechmeister (left) and Maximilian Raab (right) demonstrate the fluorescence of a perylene bisimide solution. Credit: Image courtesy of Vienna University of Technology, TU Vienna

Perylene bisimides are a heavily investigated and sought after class of organic pigments, since they show interesting dye properties. While these compounds are red pigments in the solid state, when dissolved, they generate bright yellowish-green solutions under UV irradiation. Aside their optical appeal; organic molecules that appear colored in daylight often also show intriguing electronic properties. Thus, organic dyes are promising lightweight materials for application as e.g. organic semiconductors, but also in for instance LCD displays or solar cells.

The laboratory of Dr. Miriam M...