Researchers Discover Explosive Silicon

Feb. 4, 2002 -- With the rise of computer processing power, there's no doubt to the might of silicon. But researchers recently discovered a potential new use for the material — a discovery that literally popped up in their faces.

In an attempt to develop highly sensitive magnetic sensors, scientists at the University of California: San Diego, coated silicon wafers with gadolinium nitrate.

But when Frederic Mikulec, one of the researchers at UCSD, went to cut the chip with a diamond-tipped cutter, an unexpected event occurred.

The chip blew up in his face.

Michael Sailor, a chemistry professor and head of the research project, says the violent reaction — equal to the bang from a toy cap pistol — was quite the accidental discovery.

Watch: Chip Made with Silicon 'Gunpowder' Blasts Off

Although chemists have long known that using potassium nitrate could create explosive silicon, this was the first time another common salt compound produced the same results.

"It was really surprising to us," says Sailor. "It's as if you were used to handling an ordinary, safe floppy disk and then someone comes along and says if you do this to it, it will blow up."

The Creation of Silicon ‘Gunpowder’

While the results were unintentional, Sailor says in hindsight, it shouldn't have been unexpected. "We took a look at [gadolinium nitrate] and it's a close relative to potassium nitrate — the saltpeter used to make gunpowder," he says.

Combine that with the super-fine crystals of silicon instead of the carbon in ordinary gunpowder and Sailor says you have the team's explosive material.

Further tests need to be conducted on just how big a bang can be created from the new silicon gunpowder, but Sailor says initial research seems promising. "It's got as much energy as [ordinary] gunpowder on a pound-for-pound basis," says Sailor.

What's more, Sailor says that the process of adding gadolinium nitrate to silicon isn't hard to do and could easily be incorporated into current computer chip fabrication techniques. And that could lead to a whole slew of new possibilities and applications.

Chips Designed to Self-Destruct

Most dramatic, Sailor notes, would be the self-destructing computer chip.

Since the basic building material is the same, Sailor says sensitive chips — say the ones used in secretive spy equipment or weapon systems — could have a portion crafted with silicon gunpowder. If the devices fell into the wrong hands, a signal could be sent to the chip to divert a tiny electrical pulse to the gunpowder and destroy the chip.

But Sailor says the powerful compound is good for more than just destructive power.

Powering Tiny Spies and Spotting Chemical Hazards

For example, if the force of the explosion could be controlled, the compound could be used to make tiny rockets that would power microscopic machines. "We could build a tiny robot sensor to detect chemical warfare agents that could hop around the battlefield using [silicon gunpowder]," says Sailor.

And the material could even be used to create small portable spectrometers — devices that detect chemicals by burning samples and analyzing the colors given off in the flames. "You could put 20 little furnaces on a chip and do analysis in the field," says Sailor. "When you need to do more, you just put in a new chip."

But, it will still take a number of years before the world will see tiny rockets or even computers purposely designed to self-destruct.

For one, Sailor says he and his team still need to research just how powerful they can make the material. And work must be done on developing better formulas to improve the material's combustion and possibly steer it for propulsion purposes.

But once those issues are resolved, there's no doubt that silicon will lead to a powerful leap into the future.