Category Physics

Illustration of the polar directions in relaxor-ferroelectric solid solutions where a small amount of polar nanoregions embedded in a long-range ferroelectric domain leads to dramatically enhanced piezoelectric and dielectric properties. Credit: Xiaoxing Cheng/ Penn State

All ferroelectric materials possess piezoelectricity in which an applied mechanical force can generate an electrical current and an applied electrical field can elicit a mechanical response. Ferroelectric materials are used in a wide variety of industrial applications, from ultrasound and sonar to capacitors, transducers, vibration sensors and ultrasensitive infrared cameras...

Researchers created an optomechanical silicon bullseye disk that traps optical waves in the outermost ring via total internal reflection while the radial groves confine the mechanical waves to the same area. Credit: Thiago P. Mayer Alegre, University of Campinas

Trapping light and mechanical waves within a tiny bullseye, design could enable more sensitive motion detection. The new device is highly customizable and compatible with commercial manufacturing processes. Optomechanical devices use light to detect movement. They can be used as low-power, efficient building blocks for the accelerometers that detect the orientation and movement of a smart phone or that trigger a car’s airbag to deploy split seconds after an accident...

1. The northern clingfish (Gobiesox maeandricus) lives in Pacific Northwest waters, where it seeks out prey in the crashing waves of the intertidal Credit: Petra Ditsche 2. Credit: Christina Linkem

To create prototype suction cups that are capable of glomming onto rough, wet surfaces and staying there, Ditsche has found inspiration in clingfish. On the rocky shores of Washington State, clingfish maneuver over rocks to prey on limpets – dime-sized, snail-like invertebrates. A limpet is covered by a shell shield that hides soft organs, which are fair game if the predatory clingfish can pop it off the rock. Yet the clingfish faces its own foe: heavy forces from incoming waves that threaten to slosh it off the rocks as it searches for food...

FImage: PPPL physicist Hantao Ji in front of the Magnetic Reconnection Experiment
Credit: Elle Starkmann

Physicists at DOE PPPL have for the first time directly observed a phenomenon that had previously only been hypothesized to exist. The phenomenon, plasmoid instabilities that occur during collisional magnetic reconnection, had until this year only been observed indirectly using remote-sensing technology. They created the phenomenon where they could measure it directly and confirm its existence on the electron scale, which describes the range of motion of electrons and how quickly they move.

Plasmoid instabilities create magnetic bubbles within plasma, superhot gas whose atoms have separated into electrons and atomic nuclei...