BERKELEY, CA -- Scientists with the Ernest Orlando Lawrence Berkeley National
Laboratory (Berkeley Lab) have won two of this year's Discover Magazine
Awards for Technological Innovation. The winners were Ashok Gadgil in the environment
category for "UV Waterworks," an ultraviolet-based water purification system;
and Xiao-Dong Xiang and Peter Schultz, in the computer hardware and electronics category,
for "combinatorial synthesis," a high-speed technique for making and testing new
advanced materials.
This is the seventh year that Discover Magazine has presented
its awards which are intended to "celebrate the outstanding innovations of our time,
and specifically, the scientists, engineers, and inventors who too often are the unsung
heroes of our technological age." The two 1996 Discover Awards bring the total
to four in which Berkeley Lab scientists have played a significant role. The first was in
1993 for the design of the segmented ten meter mirror of the Keck Telescope which won in
the category of sight, and the second was for the sulphur lamp which won last year's
environment award.
"These honors are a tribute to the innovation and creativity of our scientists and
to the breadth and excellence of the work that goes on here," said Berkeley Lab
Director Charles Shank. "They are further examples of how national laboratories like
Berkeley Lab turn fundamental science into practical solutions."
Gadgil's UV Waterworks is a small simple device that uses ultraviolet light to quickly,
safely, and cheaply disinfect water of the viruses and bacteria that cause cholera,
typhoid, dysentery and other deadly diarrheal diseases.
Unlike other ultraviolet-based water purifiers, UV Waterworks does not require
pressurized water-delivery systems and electrical outlets to work. It is designed to rely
on gravity for water flow which means it can be used with any source of water, and only
needs electricity for the UV light, which means it can be powered by a car-battery or a 40
watt solar cell. The end result is that UV Waterworks offers the first practical means of
providing communities in developing nations with readily accessible supplies of safe
drinking water.
In developing nations, safe, home-delivered tap water is rare. Consequently, each year,
waterborne diseases, transmitted mainly through the drinking of unsanitary water, kill an
estimated four million children under the age of five and make adults sick enough to lose
billions of hours of work productivity and income. The two most common methods of
disinfecting water in developing nations -- chlorination and boiling -- both have
drawbacks and limitations. Chlorine disinfection requires a continual supply of chlorine
bleach and trained personnel to make sure chlorine is added to water supplies at effective
levels. Boiling is usually done over wood stoves in unvented rooms which poses health
risks of its own and contributes to air pollution and deforestation.
With UV Waterworks, passing water through ultraviolet light inactivates the DNA of
pathogens and purifies the water at a cost of about two-cents per ton. The device, which
is the size of a microwave oven, disinfects water at the rate of four gallons per minute,
which is similar to the flow from a typical American bathtub spout. A pilot project is
underway in India and a second has been proposed for South Africa. Negotiations for
licensing the technology to EEG, Inc., of Chicago are in their final stages for worldwide
use except in India, where Urminus Industries Ltd. of Bombay already holds the rights.
The combinatorial synthesis technique of Xiang and Schultz promises to dramatically
speed the pace of discovery in materials science. It allows researchers to increase the
number of chemical compounds that can be created and tested as potential new materials
from the current rate of about one a day to as many as 10,000 a day. Already the technique
has been used to discover a new family of magnetoresistive compounds, materials whose
electrical conductivity changes in the presence of a magnetic field.
Combinatorial synthesis represents a radical departure from so-called
"rational" materials design, where researchers try to predict beforehand which
specific molecular structures will yield desired properties. With combinatorial synthesis,
the strategy is one of sheer numbers -- thousands of potential structures are created and
screened to find one or more that displays the properties being sought.
Schultz, who is also a professor of chemistry at the University of California at
Berkeley, got the idea for combinatorial synthesis from the human immune system. The
immune system maintains a library of roughly one trillion differently shaped antibodies
each made up of different combinations of protein chains. When faced with an invading
agent, such as a virus, the immune system selects the antibodies from this combinatorial
library that happen to bind to the virus and creates multiple copies to fight the
infection. Schultz used the technique to invent "catalytic" antibodies --
antibodies that, because of their shape, promote certain chemical reactions -- for which
he received the 1995 Wolf Prize in Chemistry.
Though biotechnology researchers have used a combinatorial approach to screen for
potentially useful drugs but this is the first time the strategy has been applied to
materials research.
To create a "combinatorial" library of advanced materials, Xiang and Schultz
deposit thousands of distinct combinations of metal-oxide molecules onto a one-inch square
grid. The materials are deposited in a checkerboard pattern as thin-film squares and
different metal ingredients are stenciled onto the grid through cut-out "masks."
Because a different mask is used for each ingredient, each square in the grid receives a
unique combination.
Working at Berkeley Lab's Molecular Design Institute, Xiang and Schultz have already
used their combinatorial synthesis technique to discover 26 new magnetoresistive
materials. These cobalt-oxide compounds lost as much as 72-percent of their electrical
resistance in a magnetic field which is comparable to the "colossal" class of
magnetoresistance materials that are in big demand by the electronics industry. Symyx
Technology, a California start-up corporation, has licensed the combinatorial synthesis
technology from the Berkeley Lab for commercial development.
The Berkeley Lab is a U.S. Department of Energy national laboratory located in
Berkeley, California. It conducts unclassified scientific research and is managed by the
University of California.
