Lifeboat Foundation

In our daily lives, we can find many examples of manipulation of reflected waves such as mirrors to see our reflections or reflective surfaces for sound that improve auditorium acoustics. When a wave impinges on a reflective surface with a certain angle of incidence and the energy is sent back, the angle of reflection is equal to the angle of incidence. This classical reflection law is valid for any homogenous surface. Researchers at Aalto University have developed new metasurfaces for the arbitrary manipulation of reflected waves, essentially breaking the law to engineer the reflection of a surface at will.

Metasurfaces are artificial structures, composed of periodic arranged of meta-atoms at subwavelength scale. Meta-atoms are made of traditional materials but, if they are placed in a periodic manner, the surface can show many unusual effects that cannot be realized by the materials in nature. In their article published 15 February 2019 in Science Advances, the researchers use power-flow conformal metasurfaces to engineer the direction of reflected waves.

‘Existing solutions for controlling reflection of waves have low efficiency or difficult implementation,’ says Ana Díaz-Rubio, postdoctoral researcher at Aalto University. ‘We solved both of those problems. Not only did we figure out a way to design high efficient metasurfaces, we can also adapt the design for different functionalities. These metasurfaces are a versatile platform for arbitrary control of reflection.’

Continue reading “Engineered metasurfaces reflect waves in unusual directions” »

New ultralight hexagonal boron nitride material could be used in extreme-temperature applications such as spacecraft.

Researchers are using 3D printing to develop electrodes with the highest electric charge store per unit of surface area ever reported for a supercapacitor.

A research collaboration from the University of California Santa Cruz and the U.S. Department of Energy’s Lawrence Livermore National Laboratory have 3D printed a graphene aerogel that enabled them to develop a porous three-dimensional scaffold loaded with manganese oxide that yields better supercapacitor electrodes. The recently published their findings in Joule. Yat Li, a professor of chemistry and biochemistry at UC Santa Cruz, explained the breakthrough in an interview with R&D Magazine.

“So what we’re trying to address in this paper is really the loading of the materials and the amount of energy we can store,” Li said. “What we are trying to do is use a printing method to print where we can control the thickness and volume.

Continue reading “3D Printed Graphene Aerogel Enhances Supercapacitor Ability” »

After what has seemed a bit of a lapse in the timeline of their development, graphene-enabled supercapacitors may be poised to make a significant advance. Researchers at the University of California, Santa Cruz, and Lawrence Livermore Laboratory (LLNL) have developed an electrode for supercapacitors made from a graphene-based aerogel. The new supercapacitor component has the highest areal capacitance (electric charge stored per unit of surface area) ever reported for a supercapacitor.

The 3D-printing technique they leveraged to make the graphene electrode may have finally addressed the trade-offs between the gravimetric (weight), areal (surface area), and volumetric (total volume) capacitance of supercapacitor electrodes that were previously thought to be unavoidable.

In previous uses of pure graphene aerogel electrodes with high surface area, volumetric capacitance always suffered. This issue has typically been exacerbated with 3D-printed graphene aerogel electrodes; volumetric capacitance was reduced even further because of the periodic large pores between the printed filaments.

Continue reading “3D Printed Graphene Aerogel Offers Highest-Ever Capacitance for a Supercapacitor” »

Circa 2016

Researchers have developed a new dry adhesive that not only bonds in extreme temperatures, it even gets stronger as the heat goes up. The gecko-inspired material maintains its hold in extreme cold and actually gets stickier in extreme heat.

Circa 2018

Scientists say 1cu cm of the material won’t break under the weight of 800 tonnes.

Form of carbon incorporated into concrete created stronger, more water-resistant composite material that could reduce emissions.

A material that alters it’s heat transfer ability depending on your temperature. Of course, it’s based on the amount of sweat you produce, which should be tied to your exertion level.

This would be good. Especially for space suit applications.

Material responds to moisture by becoming more porous and can dissipate infrared radiation more effectively too.

Continue reading “Smart textile uses sweat as switch to keep wearer cool or warm” »

The material responds to the body’s heat and wetness to help keep us at a comfortable temperature at all times.