Posted on 06/12/2007 2:43:58 PM PDT by null and void
Lilliputian Systems invented a microchip-size fuel cell that can run your cell phone for a week.
A couple of years ago it seemed that the battery era was coming to an end. In a flurry of announcements, Japanese manufacturers including Toshiba and NEC said they'd soon be rolling out miniature fuel cells to power mobile phones, music players and laptops. To recharge you'd only have to pour in some more alcohol. Consumers would be freed from the tyranny of the wall plug.
And then, radio silence. None of the promised fuel cells has hit the market. The materials inside these fuel cells are touchy about changes in temperature and humidity and prone to their own form of carbon monoxide poisoning. The best these portable fuel cells can perform is about as well as the lithium batteries they're meant to supplant.
Perhaps the great minds inside the research labs in Japan were going in the wrong direction. By taking a different tack, Lilliputian Systems, a four-year-old Wilmington, Massachusetts firm, has produced a matchbox-size fuel cell that can put out enough electricity to run a laptop computer for days. Instead of alcohol, it runs on butane, a cheap and far more potent source of energy by volume.
While Lilliputian hasn't announced an agreement with a big manufacturer, Chief Executive Kenneth Lazarus says he's talking to most of them. He figures the company's first product will be a portable battery recharger for laptops and smart phones. Current rechargers using flashlight batteries cost as much as $5 per charge, while a Lilliputian device could get 25 charges from a $2 cartridge of butane. Mass production should be easy because Lilliputian's fuel-cell chip can be made using 20-year-old semiconductor manufacturing equipment prevalent throughout Asia.
"Even if the battery manufacturers drop their price to zero, we'll kill 'em," he says. Lazarus has raised $40 million to date from Atlas Venture, Kleiner Perkins Caufield & Byers and other venture capital firms.
Lilliputian's fuel cell has been approved for use on commercial aircraft by the International Civil Aviation Organization and a United Nations body that regulates shipment of hazardous materials. Approval from the U.S. Department of Transportation is expected later this year. (The only reason butane cigarette lighters are banned is that they come with their own ignition source, the flint. A Lilliputian fuel cell is nearly impossible to ignite because you'd need to crack it open and strike a match at the same time.)
There are two dominant flavors of fuel cell: proton-exchange membrane (PEM) and solid oxide. Both inject fuel and air into opposite sides of a membrane. In a PEM cell the membrane is coated with a catalyst that strips electrons from the fuel, usually hydrogen. The now positively charged hydrogen atoms migrate through the membrane to combine with oxygen on the air side to create water. Meanwhile, the hydrogen's stripped-off electrons race around the outside, trying to rejoin their ions, generating current in the process. A solid-oxide fuel cell does the reverse: The oxygen atoms on the air side migrate through the membrane carrying two electrons that have flown around from the fuel side. The highly reactive oxygen combines with hydrogen and carbon monoxide on the fuel side to make water and CO2.
PEM cells have been in use since the 1960s and operate at acceptably low temperatures (350 degrees Fahrenheit). Yet they have drawbacks. They require pure hydrogen to produce electricity, and no one has figured out an economical way to store and transport that fuel. That's why consumer electronics makers are developing PEM cells that run on the more convenient methanol. But methanol is a weak energy source.
Solid-oxide cells, Lilliputian's choice, were abandoned by most manufacturers for use in portable power because they operate at scorching temperatures (up to 2,500 degrees Fahrenheit). But solid-oxide fuel cells are hardier and offer far more punch because they can use denser hydrocarbons as fuel. In liquid form, butane has an energy density of 7.4 kilowatt-hours per liter. Methanol, the usual PEM fuel, delivers 4.4 kwh per liter. Lithium batteries can manage only 0.3. "If you want to beat a battery, you have to beat a battery's energy density," says Lazarus. "One of the highest-density fuels is butane."
Lilliputian's engineering miracle was in designing a tiny solid-oxide fuel cell that instead of melting everything in its vicinity is merely warm to the touch. "The big idea is keeping the heat in," says Lazarus. "That's the trick."
Combining high-energy fuel with scorching temperatures is the specialty of Lilliputian's founders, Samuel Schaevitz and Aleks Franz. While at the Massachusetts Institute of Technology in the 1990s they experimented with thimble-size reactors etched into silicon wafers to produce toxic chemicals. It was blue-sky research, but their idea was that harmful substances should be produced where they are needed, instead of being shipped in bulk from chemical factories. That work is still ongoing at MIT, but the pair left, with the idea of using the same silicon micromachining technology to build tiny "reformers" that could separate pure hydrogen from alcohol for fuel cells.
Ken Lazarus, 43, joined Lilliputian in late 2003 when Schaevitz and Franz were still working in a one-room laboratory. Lazarus, an MIT-trained aeronautical engineer, was looking for something to do after having sold his previous company, Active Control Experts, or ACX, to Cymer for $35 million in 2001. Lazarus knows about turning cool technology into commercial products: ACX used piezoelectric solids, which generate electricity when they are bent, to produce vibration dampers in K2 skis.
Lazarus and the MIT duo looked into miniature PEM cells, but they soon faced the same fact now confronting the Japanese. Cells that run on alcohol don't produce enough electricity to be competitive with lithium. That's when the MIT duo decided to miniaturize a solid-oxide fuel cell instead. One of the biggest challenges was figuring out how to integrate the ceramic electrolyte into the silicon. The ceramics they were using expanded four times as fast as silicon when heated. The solution Lilliputian came up with is a trade secret, but the company does admit it uses a network of fractures to absorb the stress, much like the expansion joints in a sidewalk.
Lilliputian also had to figure out a way to keep the enormous heat of the reaction contained in a small space. Some of the heat is useful. It cracks the butane into hydrogen and carbon to keep the reaction going. The solution was a vacuum cap that sits over the whole unit, much like the glass globe surrounding the tungsten filament in a flashlight bulb.
Some of the industry giants who announced fuel cells a few years ago swear they are finally on the verge of manufacturing them in quantity. Toshiba, which displayed methanol fuel cells for music players and other devices at a Japanese trade show in 2005, says it plans to start selling them next year. Publicly traded Mechanical Technology has recruited Gillette to produce methanol fuel cartridges and has an agreement with Samsung Electronics to build prototypes. It plans to begin selling them 2008.
The U.S. military has had its eye on miniature fuel cells for some time and has financed research at Lawrence Livermore National Laboratory and elsewhere. Given where nanotechnology is headed, it's not inconceivable that they can someday be shrunk down to flea size to power injectable sensors and miniature medical devices.
Inside the Fuel Cell On a Chip
Lilliputian Systems has built a miniature fuel cell using techniques familiar to anyone in the semiconductor business. Its energy source is butane, which is converted in a fuel processor into hydrogen and carbon monoxide. Those atoms flow through miniature tubes etched in silicon to an array of tiny fuel cells. In each cell is a catalyst that strips the fuel atoms of electrons while atmospheric oxygen migrates through an electrolyte membrane carrying replacement electrons. The flow of electrons creates current, and the by-products are water vapor and CO2.
Butane? Alcohol? I can envision travel through airports as total nightmares.
And last I checked, travel through an airport is a total nightmare...
Freed from the "tyranny" of the wall plug, only to plunge into high-margin "consumables" hell, like printer cartridges. Toshiba and NEC couldn't figure out how to profit from the refill. It's going to take some sort of extra-special, super-duper butane, you can bet on that. I'll take the wall plug, lol.
So a Laptop is gonna leave a wet spot?
Probably still a few years away, but this sort of device could be used to power some micro- and nano- devices. A huge number of industrial and medical applications spring to mind immediately.
We ain’t near done reinventing the wheel yet, folks. It may not be perpetual motion, but a lot of work output for minimal input sounds closer and closer.
Do it on butane, hmm?
And you thought that was just for fireplace lighters.
*shrug* It’s a design feature...
Given that a few ml of butane would run a laptop all day, a can you could hide in your fist is a couple month’s supply.
Recharging is no more difficult than sticking a pencil point into a Cherrio, and takes seconds.
Wrong. PEM fuel cells will run directly on methanol. Their efficiency is lower than for hydrogen, but the WILL produce electricity.
Then there's the sugar lobby...
“So a Laptop is gonna leave a wet spot?”
Oh, I get it. I thought you said lap dance.
I would think you could refill it just as you would any re-chargeable butane lighter, from a larger can of butane currently sold for exactly that purpose (i.e. refilling cigarette lighters).
MeOH isn't particularly energy dense, though.
Lilliputian was going for a high energy density system.
Cool.
Or not so cool. A hot idea? 8<)
(Waiting for hammer to drop on these guys because some nitwit in the fed government gets afraid of some “explosive/security/”they’ll make a bomb out of it”/it emits/burns/uses/looks like carbon hype ....
How come I never hear about these kind of start-ups until after they get their money? And start getting their profits?
Bingo! ADM...
Water vapor and CO2 are what “global warming” nuts
want to get rid of. Carbon credits anyone?
FReepmail me for an NDA, and maybe we can talk!
Nope. Cracking not necessary.
http://mtrl1.mne.psu.edu/Document/imece2001.pdf
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