Friday, April 18, 2014
YOLO COUNTY NEWS
99 CENTS

LED pioneer Woodall turns focus to energy, water

Woodall1w

Professor Jerry Woodall works in his lab at UC Davis. Gregory Urquiaga, UC Davis/Courtesy photo

By
From page A1 | December 12, 2013 | Leave Comment

You might not know what “lattice-matched heterojunctions” are, but if you stopped at a new stoplight, played a DVD or used a laser pointer, you’ve made use of technology pioneered by Jerry Woodall, distinguished professor of electrical and computer engineering at the UC Davis.

Woodall, who has published more than 350 papers and owns 85 patents, has received wide recognition, including receiving the National Medal of Technology and Innovation from President George W. Bush in 2001. This month, Woodall adds another honor with election to the National Academy of Inventors.

This year’s new fellows will be formally inducted into the National Academy of Inventors on March 7 by Margaret Focarino, U.S. commissioner for patents, during a ceremony at the U.S. Patent and Trademark Office headquarters in Alexandria, Va.

Woodall’s work, begun in the 1960s at IBM Research, is the basis for cheap, energy-efficient light-emitting diodes, or LEDs, and lasers.

But Woodall isn’t done with inventing. He is now venturing into two of engineering’s “grand challenges” in energy and water, using discoveries he made on the way to creating high-efficiency infra-red and red LEDs.

When Woodall started his career at IBM, his employer was looking for another transistor: amplifiers, rather than light-emitting devices.

Woodall found ways to make junctions between two different semiconductors so that the combined device would emit light efficiently. The difference in “bandgap energy” between the two materials determines the wavelength of emitted light particles.

Others had made inefficient red or low-brightness LEDs based on combinations of the semiconductors gallium arsenide and gallium phosphide, but Woodall found the right combination of gallium arsenide and aluminum arsenide to make the first bright, efficient red LED that was commercially viable.

Some may remember the red glowing displays of the first digital calculators and digital watches. The technology also made remote controls, which use infrared LEDs, feasible. And they enabled development of cheap lasers, which opened the way for everything from laser pointers and optical fiber communications to DVD players and other storage devices.

“I didn’t invent the continuous wave injection laser, but I enabled it,” Woodall said.

In the 1990s, other researchers, building on Woodall’s heterojunction work, developed blue LEDs and lasers, which made possible the high information density of high-definition (Blu-Ray) DVDs. White LEDs, which use a phosphor screen to generate bright white light, are rapidly becoming popular for energy-efficient lighting.

“It’s all based on the heterojunction,” Woodall said. “That’s why I got to shake the president’s hand.”

Woodall left IBM in 1993 and worked at Purdue and Yale universities before coming to UCD in 2012.

At this stage of his career, he’s turning to two new challenges for the world: energy and water. That’s a good match with UCD, with its depth of creative expertise from engineering to policy in both fields.

“There’s a lot more that can be done with lasers and LEDs, but it’s not what you’d call a ‘grand challenge,’ ” Woodall said. “But water is.

“I know how to make potable water remotely, generate energy and clean water and modernize a remote village,” he said.

The key is the most effective energy storage material available on Earth: aluminum.

Wait, aluminum? Isn’t that a light, silvery metal for making pots and boats and aircraft parts?

Aluminum, in fact, is the most abundant element on Earth. It does not exist naturally as a metal, because it combines with oxygen to form aluminum oxides. In fact, aluminum loves oxygen so much that if you could extract the heat involved in combining the two, you would get 8.8 kilowatt-hours per kilogram of metal. That makes aluminum a better energy store than coal.

Futurists have long looked to hydrogen as the clean future fuel to replace carbon-based fuels like coal, oil and natural gas. But while hydrogen can carry a lot of energy by weight, its density is very low — you need an enormous volume to carry a significant amount of energy, or you need to store compressed hydrogen under high pressure.

“The energy density of hydrogen is good by mass but terrible by volume,” Woodall said. Aluminum, on the other hand, “can’t be beat” for energy storage by volume, he said.

Leave metallic aluminum exposed to air, and it will quickly form a skin of aluminum oxide. The secret to Woodall’s process is to find a way to oxidize aluminum while capturing heat and hydrogen. And that discovery goes back to Woodall’s early work on semiconductors.

In 1968, Woodall was trying to grow crystals in mixtures of aluminum dissolved in liquid gallium. He discovered that when water was added to the mixture, the aluminum split the water, releasing hydrogen gas and heat and forming aluminum oxides.

Since then, he’s worked to refine the process, use less gallium and make it more efficient and controllable.

Aluminum metal is made by using electricity to melt bauxite ore in a salt solution.

Woodall envisages using a solar power plant, or wind farm, to power an aluminum smelter and make aluminum metal — a compact, stable energy store. This aluminum could be used to fuel one of his reactors, generating hydrogen that runs a fuel cell that makes electricity and heat. The fuel cell also regenerates clean water, and both the gallium and the aluminum can be recycled and used again.

Woodall recently started a company, Hydroalumina, to develop and sell reactors based on the “Woodall process” that can make high-purity hydrogen or alumina.

In other projects, his lab is working on a new type of solar cell that captures energy from both light and heat, and continues to work on a truly green LED.

Over the past 50 years, Woodall’s work has made possible generations of new devices that have changed our lives but that rapidly get replaced by new gadgets. In contrast, Woodall, who describes himself as a “fairly good pianist,” keeps a Steinway at home that “will never wear out,” he says.

In July this year, he volunteered to play for a music appreciation class held in the Mondavi Center’s Jackson Hall.

“To play in a real concert hall, that fulfilled a bucket list item for me,” he said. “Better than shaking hands with the president.”

— UC Davis News

LEAVE A COMMENT

Discussion | No comments

The Davis Enterprise does not necessarily condone the comments here, nor does it review every post. Read our full policy

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Going green at church, school, everywhere

    By Special to The Enterprise | From Page: A1 | Gallery

     
    Former caretaker convicted of murder, elder abuse

    By Lauren Keene | From Page: A1, 4 Comments | Gallery

    Old friend helps Brad and others find kidneys

    By Dave Jones | From Page: A1 | Gallery

     
    Chuck Rairdan joins school board race

    By Jeff Hudson | From Page: A1, 2 Comments

     
    Ukraine insurgents reject call to quit buildings

    By The Associated Press | From Page: A2, 3 Comments

     
    For the record

    By Enterprise staff | From Page: A2

    UCD to host Global Health Day event

    By Cory Golden | From Page: A2

     
    Need a new best friend?

    By Enterprise staff | From Page: A3 | Gallery

     
    ‘Hitchhiking’ dog looking for new home

    By Lauren Keene | From Page: A3 | Gallery

     
    Online K-12 school holds info night

    By Enterprise staff | From Page: A4

    Volkssporting Club plans North Davis walks

    By Enterprise staff | From Page: A4

     
    Schwenger lawn signs available

    By Anne Ternus-Bellamy | From Page: A4

    Volunteers needed for Grad Night

    By Enterprise staff | From Page: A4

     
    Davis grad makes rain collection a business

    By Jason McAlister | From Page: A4 | Gallery

    A few spots left on history tour

    By Enterprise staff | From Page: A4

     
    Chipotle fundraiser boosts Emerson tech upgrade

    By Enterprise staff | From Page: A4

    Event to provide nature scholarship

    By Enterprise staff | From Page: A4

     
    Students have new options on leasing front

    By Enterprise staff | From Page: A5 | Gallery

    Groups join for a day of service

    By Special to The Enterprise | From Page: A7

     
    NAMI backers walk in Sacramento

    By Special to The Enterprise | From Page: A8

     
    Food for the hungry

    By Enterprise staff | From Page: A10

    .

    Forum

    Dad makes mom look bad

    By Special to The Enterprise | From Page: B5

     
    Early help is a great investment

    By Letters to the Editor | From Page: A6

    More tax money? Answer the question

    By Rich Rifkin | From Page: A6, 4 Comments

     
    UCD IS responsible for students

    By Letters to the Editor | From Page: A6, 4 Comments

     
    Tom Meyer cartoon

    By Debbie Davis | From Page: A6

    In search of great ideas

    By Letters to the Editor | From Page: A6, 1 Comment

     
    Please keep the nursery open

    By Letters to the Editor | From Page: A6

    .

    Sports

    Sharks double up Kings in Game 1

    By The Associated Press | From Page: B1

     
    Aggies lose a slugfest in opener at Riverside

    By Enterprise staff | From Page: B1

    Fox coming to UCD; Riffle heads to Florida

    By Bruce Gallaudet | From Page: B1

     
    DHS’ Golston goes full-bore on the diamond

    By Thomas Oide | From Page: B1 | Gallery

    Devils show more life in loss to Mitty

    By Enterprise staff | From Page: B1

     
    DYSA roundup: Intensity has big week; 10U games dominate schedule

    By Enterprise staff | From Page: B2 | Gallery

    Sports briefs: Aggies set the academic bar high

    By Enterprise staff | From Page: B8 | Gallery

     
    Pro baseball roundup: Susac sends Sacramento to a rare loss

    By The Associated Press | From Page: B8

    .

    Features

    .

    Arts

    ‘Transcendence’: A whole new level of tedium

    By Derrick Bang | From Page: A11 | Gallery

     
    ‘The Bloom’ paves way for Whole Earth Festival

    By Enterprise staff | From Page: A11

    DHS tribute to Tony Fields slated for April 25-26

    By Enterprise staff | From Page: A11

     
    UCD, city team up for Music on the Green

    By Enterprise staff | From Page: A11

    .

    Business

    Ford turns its Focus to domestic market

    By Ali Arsham | From Page: B3 | Gallery

     
    .

    Obituaries

    .

    Comics

    Comics: Friday, April 18, 2014

    By Creator | From Page: A9

     
    .

    Real Estate Review

    Featured Listing

    By Zack Snow | From Page: RER1

    Professional Services Directory

    By Zack Snow | From Page: RER2

    Lyon Real Estate

    By Zack Snow | From Page: RER3

    Yolo FCU

    By Zack Snow | From Page: RER4

    Acacia at Huntington Square

    By Zack Snow | From Page: RER4

    Jamie Madison

    By Zack Snow | From Page: RER4

    Travis Credit Union

    By Zack Snow | From Page: RER5

    Kim Eichorn

    By Zack Snow | From Page: RER6

    Suzanne Kimmel

    By Zack Snow | From Page: RER6

    Lynne Wegner

    By Zack Snow | From Page: RER7

    Kim Merrel Lamb

    By Zack Snow | From Page: RER7

    Patricia Echevarria

    By Zack Snow | From Page: RER8

    Chris Snow

    By Zack Snow | From Page: RER8

    Andrew Dowling

    By Zack Snow | From Page: RER9

    Sheryl Patterson

    By Zack Snow | From Page: RER9

    Don Guthrie

    By Zack Snow | From Page: RER9

    Coldwell Banker

    By Zack Snow | From Page: RER10

    Coldwell Banker

    By Zack Snow | From Page: RER11

    Heather Barnes

    By Zack Snow | From Page: RER12

    Julie Partain & Dick Partain

    By Zack Snow | From Page: RER12

    Malek Baroody

    By Zack Snow | From Page: RER13

    Willowbank Park

    By Zack Snow | From Page: RER14

    Karen Waggoner

    By Zack Snow | From Page: RER14

    Team Traverso

    By Zack Snow | From Page: RER15

    Julie Leonard

    By Zack Snow | From Page: RER15

    Tim Harrison

    By Zack Snow | From Page: RER15

    Tracy Harris

    By Zack Snow | From Page: RER16

    Lori Prizmich

    By Zack Snow | From Page: RER16

    Raul Zamora

    By Zack Snow | From Page: RER17

    Joe Kaplan

    By Zack Snow | From Page: RER17

    Coldwell Banker

    By Zack Snow | From Page: RER18

    Open House Map

    By Zack Snow | From Page: RER19

    F1rst Street Real Estate

    By Zack Snow | From Page: RER20