Category Physics

Coupling the Leidenfrost Effect and Elastic Deformations to Power Sustained Bouncing, Nature Physics, DOI: 10.1038/nphys4194

Water droplets float in a hot pan because of Leidenfrost effect. Now, physicists have discovered a variation: the elastic Leidenfrost effect. It explains why hydrogel balls jump around on a hot plate making high-pitched sounds. Physicist Scott Waitukaitis (Leiden University / AMOLF) stumbled across a YouTube video of bouncing hydrogel balls on a hot plate and was so inspired that he decided to write an NWO Veni grant proposal to explore the phenomenon.

The dance of water droplets in a frying pan is a well-known phenomenon called the Leidenfrost effect. The warm undersides of the droplets vaporize so quickly that they float around on a cushion of vapor...

1. A schematic of the sampling device built by researchers to measure levels of toxic particulate matter present during rush hour inside of a typical car cabin
2. A dashboard view from a vehicle taking measurements of certain types of pollutants during rush hour in Atlanta

In-car air study of commuting cars finds dangers to human health. The first in-car measurements of exposure to pollutants that cause oxidative stress during rush hour commutes has turned up potentially alarming results. The levels of some forms of harmful particulate matter inside car cabins was found to be twice as high as previously believed. Most traffic pollution sensors are placed on the ground alongside the road and take continuous samples for a 24-hour period...

The vinebot is a tube of soft material that grows in one direction. Credit: L.A. Cicero/Stanford News Service

A newly developed vine-like robot can grow across long distances without moving its whole body. It could prove useful in search and rescue operations and medical applications. Imagine rescuers searching for people in the rubble of a collapsed building. Instead of digging through the debris by hand or having dogs sniff for signs of life, they bring out a small, air-tight cylinder. They place the device at the entrance of the debris and flip a switch. From one end of the cylinder, a tendril extends into the mass of stones and dirt, like a fast-climbing vine. A camera at the tip of the tendril gives rescuers a view of the otherwise unreachable places beneath the rubble.

This is just o...

1. Lithium titanate Crystal structure with bulk continuum
2. A zoomed-up image of the atomic arrangement on the LiTi2O4 film surface
The three-fold symmetry indicated here reveals the spinel crystal structure.

Researchers have applied advanced scanning methods to visualize the previously unexplored surface of a superconductor: lithium titanate. Researchers at Tokyo Institute of Technology, Tohoku University and the University of Tokyo have applied advanced scanning methods to visualize the previously unexplored surface of a superconductor: lithium titanate (LiTi2O4).

LiTi2O4 is the only known example of a spinel oxide superconductor...