LED, Microscopy Pioneers Earn Nobels In Physics, Chemistry

Photonics enjoyed a brighter global spotlight than usual last month, as both the physics and chemistry Nobel prizes were awarded to recognize significant advances in light-based technologies: blue LEDs and superresolution microscopy.

The physics prize honored Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their work developing gallium nitride-based blue LEDs in the early 1990s. The trio’s work “triggered a fundamental transformation of lighting technology,” according to the Royal Swedish Academy of Sciences, which awarded the prize.

“Red and green diodes had been around for a long time, but without blue light, white lamps could not be created,” the society wrote in a statement. “Despite considerable efforts, both in the scientific community and in industry, the blue LED had remained a challenge for three decades.”

Blue LEDs enable production of white light, which will reduce global lighting costs.

Akasaki and Amano worked together at the University of Nagoya while Nakamura was employed at Nichia Chemicals in Tokushima, Japan. Nakamura is now a professor at the University of California, Santa Barbara.

“As about one-fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth’s resources,” the society wrote. “Materials consumption is also diminished as LEDs last up to 100,000 hours, compared to 1000 hours for incandescent bulbs and 10,000 hours for fluorescent lights.”

“Incandescent lightbulbs lit the 20th century; the 21st century will be lit by LED lamps,” the society wrote.

“It is very satisfying to see that my dream of LED lighting has become a reality,” Nakamura said. “I hope that energy-efficient LED lightbulbs will help reduce energy use and lower the cost of lighting worldwide.”

The chemistry prize went to Eric Betzig, Stefan W. Hell and W.E. Moerner for their work on circumventing the diffraction limit to achieve nanoscale microscope images.

STED microscopy (circular inset image) provides an approximately 10 times sharper image of filament structures within a nerve cell compared with a conventional light microscope (outer image). Photo courtesy of Max Planck Institute for Biophysical Chemistry.

Hell, director of the Max Planck Institute for Biophysical Chemistry in Goettingen, Germany, was recognized for developing stimulated emission depletion (STED) microscopy, which uses one laser beam to stimulate fluorescence in molecules and another to cancel out all fluorescence except for that at the nanoscale.

Betzig and Moerner, working separately, developed single-molecule microscopy. The method relies on turning individual molecules’ fluorescence on and off. The same area is imaged multiple times, with just a few interspersed molecules allowed to glow each time. Superimposing these images yields a dense image with nanoscale detail.

Betzig, of the Howard Hughes Medical Institute’s Janelia Farm Research Campus in Ashburn, Va., used this method for the first time in 2006. Moerner is a professor at Stanford University.

Physics Winners are Isamu Akasaki, Hiroshi Amano and Shuji Nakamura.

“Today, nanoscopy is used worldwide, and new knowledge of greatest benefit to mankind is produced on a daily basis,” the society wrote.

The techniques developed by Hell, Betzig and Moerner have enabled scientists to see how molecules create synapses between nerve cells in the brain, track proteins involved in Parkinson’s, Alzheimer’s and Huntington’s diseases, and follow individual proteins in fertilized eggs as they divide into embryos.

Chemistry Winners are Eric Betzig, Stefan W. Hell and W.E. Moerner.

Conventional light microscopes reach their resolution limit when two similar objects are closer than 200 nm because the diffraction of light blurs them to a single image feature. In 1873, German microscopist Ernst Abbe declared that this was the limit of microscopy – and so it was for more than a century.

But Hell thought differently, and went on to develop the STED technique in 1999. “Back then I intuitively felt that something has not been thought through thoroughly,” he said.

STED microscopy is capable of imaging labeled protein complexes with a separation of 20 to 50 nm. It can also image fast movements within living cells with a resolution of 65 to 70 nm – three to four times better than conventional light microscopes.

Each group of three will split a prize of 8 million Swedish kronor (about $1.11 million).