Solar panels and other solar-powered devices are fueling the future, with new applications being developed all the time. Those finding solar power success include cameras, lights, sensors and even some household appliances. And now – airplanes? Imagine relying on solar power to run an entire airplane. It’s a mind-boggling concept, but one that has become a reality. Swiss pilot André Borschberg is on a mission to fly the Solar Impulse 2 around the world, relying solely on solar power. He recently completed the longest leg of the journey – over the Pacific Ocean from China to Hawaii. Built into the wings of the Solar Impulse 2 are 17,000+ solar cells, which power the engines and recharge the batteries for night flying. Part of the Solar Impulse program, the journey began in Abu Dhabi in March, with stops in Oman, India and Myanmar. This project brings to light the many possibilities presented by solar power, such as turning carbon dioxide emissions into plastics, drugs and fuels – with a little help from the sun. Lingering a little longer in the sunlight, this month’s Green Light section presents an artificial photosynthesis process that captures CO2 emissions and ultimately converts them into useful chemical products. Carried out by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California, Berkeley, the work has achieved a solar energy conversion efficiency of up to 0.38 percent for about 200 hours under simulated sunlight – about the same as that of a natural leaf. In our cover story, “Materials Innovations Help LEDs Turn On,” beginning on page 38, contributing editor Hank Hogan tells us how changes in materials are cutting costs and boosting performance. Also featured in this issue: • “Layer Structure Enhances Light Absorption,” by Haihua Tang, Yunfei Liu, Shuang Liu, Dejun Chen, Yong Liu and Zhiyong Zhong, University of Electronic Science and Technology of China, Chengdu, beginning on page 42; • “Applied Robotics: How Robots are Changing our World,” by science writer Valerie C. Coffey, beginning on page 46; • “Quantum Cascade Lasers: Where They Are and Where They’re Going,” by Photonics Spectra staff, beginning on page 51; and, • “Considerations When Buying Flat Optics,” by Michael Naselaris, Sydor Optics, beginning on page 54. Apply sunscreen, and turn the page. Happy reading!