Category Technology/Electronics

Optically-driven mechanical oscillator fabricated using a plasmomechanical metamaterial.

A device fabricated using a plasmomechanical metamaterial, operates through a unique mechanism that couples its optical and mechanical resonances, enabling it to oscillate indefinitely using energy absorbed from light. This work demonstrates a metamaterial-based approach to develop an optically-driven mechanical oscillator. The device can potentially be used as a new frequency reference to accurately keep time in GPS, computers, wristwatches and other devices. Other potential applications include high precision sensors and quantum transducers.

Researchers engineered the metamaterial-based device by integrating tiny light absorbing nanoantennas onto nanomechanical oscillators...

The schematic depicts the time-resolved photoemission electron microscopy instrumentation that allowed the Femtosecond Spectroscopy Unit to visualize electron movements. The 800nm pump pulse (red) excites electrons while the weaker 266nm probing pulse (blue) allows for different measurements of electron movements to be taken. Credit: Michael Man

Ever since J.J. Thompson’s 1897 discovery of the electron, scientists have attempted to describe the subatomic particle’s motion using a variety of different means. New research from the Femtosecond Spectroscopy Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) has made this process much easier.

I wanted to see the electrons move, not just to explain their motion by measuring a change of light transmission and refle...

Photograph and schematic lay-out of the experimental setup, featuring an improved flow field design and a reduced thickness of the graphite window (500 µm). The latter is transparent to X-rays at the K edge energies (6 8 keV) of transition metal catalysts such as manganese, iron, cobalt and nickel. The improved cell design therefore also enables operando XAS studies of commonly investigated fuel cell catalysts based on these 3d transition metal alloys with platinum, or of PGM-free iron-based catalysts. Credit: Image courtesy of Universiteit van Amsterdam (UVA)

The structure of the palladium catalyst for hydrogen oxidation in proton exchange membrane (PEM) fuel cells has been revealed...

Turning brewery wastewater into battery power

CU Boulder engineers have developed an innovative bio-manufacturing process that uses a biological organism cultivated in brewery wastewater to create the carbon-based materials needed to make energy storage cells. This unique pairing of breweries and batteries could set up a win-win opportunity by reducing expensive wastewater treatment costs for beer makers while providing manufacturers with a more cost-effective means of creating renewable, naturally-derived fuel cell technologies.

“Breweries use about 7 barrels of water for every barrel of beer produced,” said Tyler Huggins, CU Boulder’s Department of Civil, Environmental and Architectural Engineering. “And they can’t just dump it into the sewer because it requires extra filtration...