Quantum Dot White LEDs Achieve Record Efficiency
Researchers have demonstrated nanomaterial-based white-light-emitting diodes (LEDs) that exhibit a record luminous efficiency of 105 lumens per watt. Luminous efficiency is a measure of how well a light source uses power to generate light. With further development, the new LEDs could reach efficiencies over 200 lumens per watt, making them a promising energy-efficient lighting source…
Spectral Cloaking Could Make Objects Invisible Under Realistic Conditions
Researchers and engineers have long sought ways to conceal objects by manipulating how light interacts with them. A new study offers the first demonstration of invisibility cloaking based on the manipulation of the frequency (color) of light waves as they pass through an object, a fundamentally new approach that overcomes critical shortcomings of existing cloaking…
Moisture-responsive ‘Robots’ Crawl with No External Power Source
Using an off-the-shelf camera flash, researchers turned an ordinary sheet of graphene oxide into a material that bends when exposed to moisture. They then used this material to make a spider-like crawler and claw robot that move in response to changing humidity without the need for any external power. “The development of smart materials such as moisture-responsive…
Graphene Plasmons Reach the Infrared
Graphene’s unique properties can be both a blessing and a curse to researchers, especially to those at the intersection of optical and electronic applications. These single-atom thick sheets feature highly mobile electrons on their flexible profiles, making them excellent conductors, but in general graphene sheets do not interact with light efficiently. Problematic for shorter wavelength…
A First Glimpse into Disc Shedding in the Human Eye
An elusive biological cycle in the eye – the daily disposal and regeneration of the end tips of photoreceptor cells – has been captured in images for the first time in a living human eye. Photoreceptors are light-sensitive cells responsible for initiating vision. This glimpse into the inner workings of the eye will help scientists…
Economical Technique for Imaging Multicore Fibers in Real Time
Multicore fibers (MCF) have attracted much attention in the fields of telecommunications, fiber lasers and medical endoscopes. MCF-based optical imaging techniques, which use a fiber bundle (each fiber acting like a discrete pixel to form the final pixelated image), are useful for investigating inside the human body in a minimally invasive way. Recently, there has…
New Imaging Method Reveals Nanoscale Details about DNA
Researchers have developed a new enhanced DNA imaging technique that can probe the structure of individual DNA strands at the nanoscale. Since DNA is at the root of many disease processes, the technique could help scientists gain important insights into what goes wrong when DNA becomes damaged or when other cellular processes affect gene expression.…