Power Out of Humidity. Jun Yao, a professor of engineering at the University of Massachusetts at Amherst, published a paper in Advanced Materials that shows that energy can be pulled from the moisture in the air using material that has been harvested from bacteria. The study says that almost any material can be used for this purpose as long as the material can be smashed into tiny particles and then reformed to include microscopic pores that are less than 100 nanometers in size. The tiny holes work by allowing water vapor to pass through the device in a way that creates an electric charge imbalance between the top and bottom of the device, Each nanotube is effectively a tiny battery that can continuously produce electricity.
The test devices created by the Jun Yao team have been labeled as Air-gen. One Air-gen unit is about the size of a fingernail and as thin as a hair. One unit can produce continuous energy that is strong enough to power a dot on a computer screen.
Jun Yao refers to the Air-gen as creating a tiny man-made cloud. The next step for the team is to determine the materials that produce the most electricity. There are also challenges to efficiently harvesting and storing the power from multiple Air-gen units. Making this into a useful technology will mean somehow stacking large numbers of these units together.
The potential for the technology is immense if it can ever be scaled. This would enable power to be generated locally in a way that produces no waste or byproducts. Since humidity drives the electric power generation, this would best be used in places with high humidity instead of in deserts. The ideal clean energy technology has always been described as one that can pull power out of nature – and this technology might become the ideal source of power if it can pull electricity out of the water vapor in the air.
The Anti-Laser. Physicists at the Hebrew University of Jerusalem and the Vienna University of Technology have developed what is being dubbed the anti-laser. This is a device that traps light until it is fully absorbed.
There are a lot of uses for technologies that can absorb light. Photovoltaic cells would be increasingly efficient if all light can be absorbed and turned into electricity. Light sensors could be far more precise by eliminating stray light signals. The ability to capture faint light images with a telescope could be enhanced by eliminating spurious light.
The technology takes advantage of the quantum properties of electromagnetic waves, where waveforms can undergo destructive interference if combined in an exact way. The scientists have created a device that pulses light in a way to enhance the interference. This is accompanied by a set of mirrors and lenses that trap light inside a cavity and bounce it over and over again until the light is absorbed by light-absorbing materials.
Interestingly, this mimics a phenomenon in nature. When a flashlight is shined in the eyes of animals with night vision, like owls, the light appears to be reflected back. This is due to a reflective layer that sits behind the retina of such animals. Reflecting the light back out allows two chances for the retina to capture what is being seen in the near-dark.
When the researchers started this experiment, they found that light entering the trap from different angles was not fully absorbed, and some light escaped. They solved the problem by arranging the mirrors in a way to force all light into a circular path until it is fully absorbed.