This article caught my attention because it goes toward a number of design needs that I can envision but how it also enters into some other debates. This article from Yahoo News is the one posted below.
Weird 'Heat Shrinking' Material May Prove Blessing
Sat Sep 28,12:30 PM ET
By Jeremy Smith
LONDON (Reuters) - One of the world's most unusual chemical compounds may prove a godsend for dentists, chefs and even Formula One drivers as it defies the normal laws of physics with a rare ability to shrink, not expand, when heated.
Nestling in the middle of the periodic table, zirconium may not exactly be a household name. Its ores have been known since ancient times but more so by older names: jargon, jacinth and hyacinth, some of which are mentioned in the Bible.
But more recently, one of the element's several compounds has amazed scientists with its weird behavior and sheer variety of potential commercial uses. Its name is zirconium tungstate and it could make many everyday annoyances a thing of the past.
Wild temperature swings can crack a plate as easily as dropping it on a hard kitchen floor, for example. A ceramic dish taken from the freezer and thrust into a hot oven splits apart because some parts heat up and expand faster than others.
The problem isn't unique to dishes: one of the main causes of broken fillings is thought to be thermal expansion and contraction as teeth get routinely exposed to temperatures ranging from ice cream to piping hot coffee.
But all that may change with non-toxic zirconium tungstate, a blend of zirconium, tungsten and oxygen. And several U.S. patent applications have already been lodged to exploit its main feature: a tendency to shrink, uniformly, when heat is applied.
"We have found other materials that show negative thermal expansion. However, none of these appear to be competitive with zirconium tungstate for applications," said Arthur Sleight, a professor at Oregon State University who headed the team that first discovered the strange properties of zirconium tungstate.
"The use of zirconium tungstate remains very much of interest for dental fillings...(while) electronic companies continue to show interest in using (it) to adjust the thermal expansion of circuit boards so that it matches that of silicon."
SCHOOL PHYSICS TURNED ON ITS HEAD
Schoolchildren learn at an early age that solids expand when they are heated and contract when cooled, like wooden doors that are more difficult to open in the summer due to swelling.
But a handful of solids violate this supposedly inviolable rule and contract when heat is applied, a discovery that has excited scientists with its vast commercial potential.
One of world's few known "heat shrinking" compounds, zirconium tungstate demonstrates its strange behavior over an impressively wide temperature range, from near absolute zero (-273 degrees Celsius) up to a red-hot +777 degrees.
Water also shrinks a little as it is heated, but only from freezing point to just above freezing point.
Although several materials exhibit this unusual property, zirconium tungstate is the only one known so far to show the behavior at a constant rate and at room temperature. Unlike the other compounds, it also shrinks equally in all directions.
Scientists have known something of zirconium tungstate's unusual behavior for some 30 years have only recently begun to explain why it acts so contrarily.
Now, lab technicians are testing other compounds such as copper for use as potential blends with zirconium tungstate so as to make new composite materials resistant to thermal shock.
SEEMINGLY LIMITLESS POTENTIAL
The possibilities for commercial applications appear huge.
Scientists say the new material may help overcome serious problems in electronics, metallurgy and ceramics, and eliminate distortions in optical applications such as telescopes and laser devices where very low thermal expansion is needed so that precise focusing is not lost with temperature fluctuations.
Several firms, mainly in the United States, are conducting their own research into applications for zirconium tungstate but very little has yet been published and companies say specific project developments remain commercially sensitive information.
Another possible use might be to improve performance of the high-precision engines used in Formula One racing cars by compensating for changes in size and shape.
With 10 times the horsepower of a normal road car, the complex Formula One engines have around 900 moving parts and must operate at very high temperatures -- thus rendering them liable to over-heating and distortion, leading to metal fatigue.
Silicon chips, the backbone of modern electronic circuitry, are another target for improvement as they have been known to "burn out" and self-destruct because of heat generated during use.
At present, the heat problem is worsening as smaller and smaller chips are developed and circuits get more densely packed. If the chips are mounted on material that cannot match the expansion, the silicon can crack and peel off its base.
Zirconium tungstate could guard against this and be of great benefit to the computer industry, as manufacturers blend it with other materials into circuit boards to reduce the expansion of the new compound created until it matches that of silicon.
FIBRE OPTICS MOST LIKELY APPLICATION
However, most progress has been made in fiber optics, seen as the material's most viable and probable use.
"I think the most likely application is the fibre optic one, it's likely to have the biggest impact. These are fibre gratings needed to protect certain wavelengths of light," said John Evans, chemistry lecturer at Britain's University of Durham.
Scientists hope the material's unique shrinkage properties should compensate for optical fibre variations as temperatures change, otherwise multiple wavelengths transmitted through a fibre would become a scrambled mess. Even the slightest amount of expansion or contraction can impair a signal.
"It's potentially a very big market, and zirconium tungstate is an ideal material for this application," Evans said.
