Engine On a Chip May Beat the Battery

Krishna Dagli writes, "MIT researchers are putting a tiny gas-turbine engine inside a silicon chip about the size of a quarter. The resulting device could run 10 times longer than a battery of the same weight, powering laptops, cell phones, radios, and other electronic devices." From the article: "All the parts work. We're now trying to get them all to work on the same day on the same lab bench." The goal is to do that by the end of the year.

Re:Cripes!

[eko33]

Arrrrrrrrrrrrrrrrrrrrr! Ye' have never fought the likes o' a man eat'n shark with lasers atop their skulls!

Pffft! Chips with lasers! You yellow-belly land-lubber!

double cripes!

[ccozan]

Today they made a miniprojector: http://news.bbc.co.uk/2/hi/technology/5359724.stm [bbc.co.uk]

Re:Generator?

[Tx]

OK, I can picture the gas microturbine, and I can picture how a fuel/combustion energy source can outpower an electochemical energy source. However, do we have the capacity to make a generator that small.

As usual, the answer is in TFA, and it is "Yes":

Turbine blades, made of low-defect, high-strength microfabricated materials, spin at 20,000 revolutions per second -- 100 times faster than those in jet engines. A mini-generator produces 10 watts of power. A little compressor raises the pressure of air in preparation for combustion. And cooling (always a challenge in hot microdevices) appears manageable by sending the compression air around the outside of the combustor.

Re:Polution?

[egomaniac]

The main reason that lawnmower engines are so incredibly dirty is that they are two-stroke engines. Two-stroke engines are inherently evil -- they burn dirty and emit huge quantities of unburnt fuel -- but they have a higher power-to-weight ratio and therefore see use where a small, powerful engine is required. It has a lot more to do with the engine design than it does the size. As for the pollution controls in cars, don't forget that car engines have to deal with an incredibly wide range of ever-changing speeds and power requirements. It's quite difficult to build an efficient engine which operates across such a wide range of speeds, but a simple engine driving a generator can operate at precisely one speed with a fixed load and can therefore be optimized for its precise requirements.

Further. the researchers in TFA are not building a piston-driven engine at all, they are building a gas-turbine engine. While it's difficult to speculate on the efficiency at this point (the thing doesn't even exist!), I would expect it to be relatively clean.

Re:I wonder how safe they will be?

[Anonymous Coward]

20,000/100 = 200

Jet engines spin at 200 RPM?

And we thought bad math on unmanned mars probes was scary. Hope this guy is sticking with journalism.

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[account_deleted]

Comment removed based on user account deletion

Re:Hot exhaust?

[necro81]

One thing that many people forget - mostly due to the impression given by hollywood - is that gasoline and diesel don't explode at the drop of a hat. But the liquid form doesn't ignite, it must first be vaporized and mixed with oxygen before you have something that will readily combust. If you had a closed container of fuel, and prevented oxygen from getting in, it would be pretty safe. Even when liquids were allowed on airplanes, there weren't many stories [possibly none - does someone know of any?] of terrorists using gasoline in a bomb, despite the fact that it is easier to get than explosives and readily concealed.

Even a gas tank, which gets filled with air as the gas is used, rarely explodes even in the most violent car crashes. Usually what happens is that the fuel gets sprayed everywhere and burns on the surface. An explosion wouldn't come from all the gas suddenly burning, as happens with a genuine explosive, but from the vapors in the tank combusting and causing the tank to rupture.

Re:Hot exhaust?

[ehud42]

[OT - but reminded me of when I was a teenager]

One thing that many people forget - mostly due to the impression given by hollywood - is that gasoline and diesel don't explode at the drop of a hat. But the liquid form doesn't ignite, it must first be vaporized and mixed with oxygen before you have something that will readily combust.

I was working for my uncle in a manufacturing plant (hopper bottom grain bins). He was cutting a piece of steel with a cutting torch. The piece was no bigger then a few square inches and was glowing bright yellow. He grabs it (with welding gloves) and tosses it into a pail of liquid nearby. From the hiss, I assumed it was water - turns out it was acetone (or some similar solvent). Extremely flamable, but I guess the metal failed to heat the fuel / air mixture to the combusting point before it was submerged in an oxygenless environment. I figured he was nuts - maybe he was. The point being, had this been hollywood, the whole plant would have exploded in a massive fireball.

Re:Hot exhaust?

[pluther]

There's no such thing as a "temporary" restriction, apparently.

It has been forbidden, in the United States, to take liquids of any kind onto an airplane ever since the so-called "foiled terrorist plot" (another name for it would be "a bunch of guys bragging to each other how they would take down an airplane if they wanted to" since it never got anywhere near the level of "plot". But I digress).

The TSA publishes an online list [tsa.gov] of restricted items.

Re:p = mv & F =ma

[MustardMan]

I must have pissed off some pussy moderator - ive been getting a lot of bullshit bogus moderation this week.