Water Purification System, Materials Library Selected For Discover's Awards
June 7, 1996
By Lynn Yarris, LCYarris@LBL.gov
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. The second was for the sulfur 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."
Secretary of Energy Hazel O'Leary came to the Lab on Tuesday to publicly
congratulate the winning scientists and have a personal demonstration of
Gadgil's technology.
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 diseases.
Unlike other ultraviolet-based water purifiers, UV Waterworks does not require
pressurized water-delivery systems and electrical outlets. It is designed to
rely on gravity for water flow, which means it can be used with any source of
water. It only needs electricity for the UV light, which means it can be
powered by a car battery or a 40-watt solar cell.
In developing nations, safe, home-delivered tap water is rare. Each year,
waterborne diseases, transmitted mainly through drinking 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.
The two most common methods of disinfecting water in developing
nations--chlorination and boiling--both have 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 eight cents for every
1,000 gallons. The device can disinfect water at the rate of four gallons per
minute, similar to the flow from a typical American bathtub spout.
A pilot project is under way in India and a second project has been proposed
for areas in 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.
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 those with the properties being
sought.
Schultz, who is also a professor of chemistry at Berkeley, took 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, this is the first time the strategy has been
applied to materials.
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.
Given the millions of potential compounds that exist just from the combination
of the five elements that can form metal-oxides, there is an enormous advanced
materials "universe" waiting to be discovered. Working at Berkeley Lab's
Molecular Design Institute, Xiang and Schultz have already used their
combinatorial synthesis technique to discover 26 new magnetoresistive
materials.
Symyx Technology, a California start-up corporation, has licensed the
combinatorial synthesis technology from the Berkeley Lab for commercial
development.
Berkeley Lab scientists have won two of this year's seven 1996 Discover Awards for Technological Innovation. The winners are Ashok Gadgil of the Energy and Environment Division, in the environment category for "UV Waterworks," an ultraviolet-based water purification system; and Xiao-Dong Xiang and Peter Schultz of the Materials Sciences Division, in the computer hardware and electronics category, for "combinatorial synthesis," a high-speed technique for making and testing new materials.