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.

I wonder how safe they will be?

[nizo (81281)]

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.

And you thought a hot battery in your lap was scary.

p = mv & F =ma

[by Anonymous Coward]

Since the mass of these materials is super small, the fact that they are moving at high velocity is no cause to hide under one's bed.

Also, at 20,000 rpm .. assuming that the "revolution" is a distance of 1 or 2 millimeters .. the ACTUAL velocity is nothing to send a letter home with.

Do the math (remember we are talking about the speed of the part of the object that is actually moving).

Another way of looking at it .. the total force cannot exceed the energy output of the gas expansion .. which is the result

Re:p = mv & F =ma

[gewalker (57809)]

Try 20,000 revs / sec

E = 1/2 mV^2

Mass should be small since mass/volume hase cubing scaling. I expect MIT is not too concerned about it since they did not mention it.

I used to work at Cummins research center -- watch a turbocharger burst test if you get the chance, basically dump in as much fuel/air as it takes to get the flywheel to fly apart. Test is: is the casing is strong enough to contain all the flying pieces.

Re:p = mv & F =ma

[gewalker (57809)]

Hate to reply to myself as a general rule, but I thought a little searching would pay off.

Here [cam.ac.uk] is a movie from Rolls Royce, not exactly the same, but it's nice.

Re:p = mv & F =ma

[JesseL (107722)]

Well according to another article the turbine is 4mm in diameter, so google says .5 * 4mm * pi * 20000 is about 125.6 meters. 125 meters per second is about the velocity of a low end bb gun. Given my adolecent expirimentation in terminal ballistics, a similar low end bb gun will barely penetrate both sides of a soda can. It should be a simple matter to provide the engine with a scatter shield stronger than a soda can.

Re:I wonder how safe they will be?

[Xymor (943922)]

Lasers and turbines on chips? I think this is an elaborate plan to make deadly military level pc components. With the detection of non-drm'd media, the chip will eject, fly close to you and shoot you in the face. It's the next level after "Trusted Computing", "Feared Computing".

Re:

[srk2040 (973509)]

I'd be impressed if these guys can rig up a setup that collect methane as fuel for the turbine. Imainge every small appliance running on your fart. Now that would be Nobel worthy.

Re:

[Marxist Hacker 42 (638312)]

Actually, since they're using a microcarburetor instead of a microfuel injector, I can see a whole new service industry coming from this: "Honey, I need to get some work done so I'm going down to the Internet Bar for a while". The same business could serve your Wi-Fi, your favorite microbrew, and run your laptop on shots of whiskey.

Re:

[Fred_A (10934)]

Cool, we slashdotters will finally have someone (or something) to drink with !

Re:

[drinkypoo (153816)]

What the geeks at MIT have done is to create a portable explosive device.

Short your Li-Ion battery with a nice fat conductor sometime and tell me what you get.

Disclaimer: I cannot be held responsible for any injury to person or property resulting from your potential stupid actions, whether I suggested them or not.

...or not

[Alef (605149)]

Packing a huge amount of energy into a small space is essentially creating a potential explosive.

Well, a bottle of plain water (about 1 kg of matter) contains roughly 100 petajoules (10^17 J), and still they are known to explode very infrequently. What matters is how stable the energy state is.

Cripes!

[Rob T Firefly (844560)]

Yesterday they were putting lasers on a chip. [slashdot.org] Today it's engines. Tomorrow, I suppose I'm just going to live on a chip.

Re:Cripes!

[Gothmolly (148874)]

No, tomorrow its Snakes on a Chip!

Re:Cripes!

[mobby_6kl (668092)]

>No, tomorrow its Snakes on a Chip!

And the day after tomorrow it's Apostrophes on a motherfucking Chip!

Re:

[oahazmatt (868057)]

I'm afraid that the whole snakes on a plane thing is already deader than dogshit.

Chips on a Shoulder! :)

Re:

[michaelvkim (981938)]

many of us IT junkies do live on chips...

potato chips, that is!

Re:Cripes!

[eko33 (982179)]

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 (754085)]

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

build a better battery

[Brigadier (12956)]

I guess instead of building a better battery it's build a better generator. I guess all that matters is the efficiency of the design. My question is obviously heat production, and probably not as important exhast gases. How clean will this device burn. How well will these gases coexist with heat, and ionization.

Sounds like a interesting replacement for motors too.

Re:

[anonymous_wombat (532191)]

If this is running in my house, then exhaust gases seem pretty important to me.

Wow!

[Kirin Fenrir (1001780)]

It's the energy source of the future! It's...

...gas?

Hot exhaust?

[Bryansix (761547)]

The article doesn't mention what happens to the hot exhaust after it passes through the turbine. Does this mean that have not tackled this problem yet? This could give a whole new meaning to the whole "laptop frying your balls".

Re:Hot exhaust?

[Waffle Iron (339739)]

what happens when it runs out of gas?

I'm going to go way out on a limb here and speculate that when it runs out of gas, the engine stops turning.

Re:Hot exhaust?

[necro81 (917438)]

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:

[pluther (647209)]

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.

I know where this is going...

[jakedata (585566)]

Miniature fighter jets with lasers all etched out of a silicon crystal.

We could drop half a billion of them over the middle east.

Small is not good for mechanical applications nece

[The Dalex (996138)]

That's a really interesting read (pancake analogy aside), although it sounds like the resulting device will be pretty fragile. A small grain of sand or a little dust buildup would cause complete failure. Large mechanical systems have the ability to power through minor problems like that, but such a small one will not really be suited for military field use, I imagine.

Re:Small is not good for mechanical applications n

[LWATCDR (28044)]

I have to wonder how efficient it will be. Two things drive the efficiency of a gas turbine. The heat differentials and that leakage between the blades or impeller and the housing.
The leakage is going to be a real issue since it is a ratio between the disk size and the gap. Bigger engines mean a higher ratio. That is one of the reasons that BIG gas turbines are relatively efficient while small one suck fuel like there is no tomorrow.

Generator?

[camperdave (969942)]

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. After all, we have the rotary power, how do we convert that into electrical energy?

I would be more interested in a bioelectric power source, like electric eel cells fed with sucrose.

Re:

[Smidge204 (605297)]

Any electric motor can conceivably be used as an electric generator with little modification, or in most cases no modification at all. Considering how small we can make electric motors I don't think this will be the issue.

=Smidge=

Re:

[Tx (96709)]

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 pre

Re:Generator?

[Comboman (895500)]

I would be more interested in a bioelectric power source, like electric eel cells fed with sucrose.

Electric eel generator, bird beak phonograph needle and dinosaur garbage disposal are already patented by Fred Flintstone.

What happens if...

[Lurker2288 (995635)]

...a teeny, tiny seagull flies into the turbine?

Re:What happens if...

[Duhavid (677874)]

Teeny tiny feathers fly out

All parts work, just need to put it together

[140Mandak262Jamuna (970587)]

ha, ha ha. How many times the rookies in my dept have come to me excitedly and said, "Great news Boss, Got all the functions implemented and unit testing checked out ok. All I need to do is to put it together. Finished 90% of the code in just 10% of the time. Want to take a month off to chill out in Aruba!"

Then they spend 200% of the allotted time to make sure what they wrote in the first 10% interact with one another correctly.

pointless?

[micromuncher (171881)]

A microturbine requires a completely new energy source; can you imagine plugging a butane canister into your portable? All turbines have physical issues around energy lost through heat; remember in a traditional engine only about 50% of fuel burned actually goes to perform work.

What Zippo?

[Hillgiant (916436)]

Yeah, when my laptop runs out of butane, I could just plug it into that butane outlet in the wall...

Does it expel cabon dioxide?

[tinrobot (314936)]

I would imagine if it burns a fuel, it spits out carbon.

We need to stop burning stuff for our energy. Sure, batteries store energy made by mostly burning coal and stuff, but there other options for generating electricity to fill those batteries that don't involve adding carbon. I wish these people focused their research towards these types of energy sources.

Re:Does it expel cabon dioxide?

[squiggleslash (241428)]

I'd imagine it can be tuned to run from any hydrocarbon based fuel source. Sources such as alcohol should be carbon neutral. There's nothing that says it has to be from fossil fuels.

Polution?

[iansmith (444117)]

Simple, small gas engines in lawnmowers and scooters are far, far dirtier than in a large modern car engine that has extensive polution control systems even when you take into account how much more gas a car uses than a lawnmower.

So I can't imagine this thing will run very clean at all. Not much room to put in a catalytic converter or other cleaning methods.

I have to wonder what a hundred million of these things running will do to indoor air quality. I don't think I want a thousand of these inside my office building.

Re:Polution?

[egomaniac (105476)]

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.

Why???

[thepacketmaster (574632)]

Other than the obvious geek factor, why would we want to increase our dependancy on a fossil fuel.

Re:Why???

[shrikel (535309)]

Because as we move to hybrid gas-electric vehicles, more and more mechanics are finding they need a degree in electronics just to be able to fix your car. So to level the playing field, we felt that electronics geeks should have to learn how to fix an engine too.

awesome startup sound

[llZENll (545605)]

How cool will it be when you turn your laptop on and it sounds like a jet engine starting up!

so when...

[not a cylon (1003138)]

will they be putting tiny engines inside silicon*e* ? Just imagine, breasts that swing *themselves* even when the woman is standing still. It truly would be Utopia. Or Stepford. I always get those two confused.

They should use steam. :)

[Quiet_Desperation (858215)]

Can it beat John Henry and his mighty hammer? Didn't think so!

Scaling down heat engines?

[140Mandak262Jamuna (970587)]

When steam engines were invented and developed in England by Newcomen the science of thermodynamics was lagging the technology. The steam engines work obviously but they could not get scaled down versions of the steam engines to work at all in the lab. Mainly because real engines were made with cast iron but the lab models were made with brass and it conducted away the heat away too quickly. At this time a man named James Watt, an instrumentmaker by profession did lots of work on the lab models and made an improved steam engine by mainly making the steam condense outside the cylinder. Also he invented the Watts Governor to regulate the speed of the machine. The moral of the story is that, heat engines dont scale down as easily as electronics.

Fluids in general behave much more differently in microscopic quantities than in large bulk quantities. I expect to be lugging large batteries for some time to come.

Re:

[giafly (926567)]

[Steam engines prove] that heat engines dont scale down as easily as electronics.

Steam engines of the era you're discussing [cottontimes.co.uk] heated water in a big drum, just hot enough so it turned to steam, then cooled it just enough so it condensed back to hot water. Both stages (especially the second) were critically dependent on conduction. The heat engine in the example works by burning a fuel-air mix at the the melting point of steel apparantly, and doesn't bother condensing the result. I think the issues are diffe

Wonderful

[eno2001 (527078)]

Just what we need these days, not less but MORE dependence on fossil fuels. What idiots! Besides the obvious problem of trying to fuel something that small at the gas pump and then paying for it in fractions of a penny, what about the carbon dioxide emissions that conbustion engines produce? Aren't we going to be in for a lot of people with lots of headaches and brain damage from using a device like this? Even though it's so small, it's STILL emitting carbon dioxide which is known to cause the more serious cases of fatal death. I still get behind my roaring battle cry: SOLAR POWER IS WHERE IT'S AT FOLKS!!! The sun is an abundant energy source. Amp the solar panel production up so that they are 99.999% efficient, and you won't need any other source of energy anywhere on the planet. Combine that with electricity resevoirs that can hold a couple hundred gallons of electricity, and you have a clear winner. Thumbs down on this for sure.

Murphy's Law of Engineering

[DeadCatX2 (950953)]

Everything works great until you show it to your manager...

"All the parts work. We're now trying to get them all to work on the same day on the same lab bench."

"Hey boss, c'mere! I got our engine-on-a-chip to work!"

*boss meanders on over*

*turbine stops spinning*

*boss walks away grumbling*

"Bbbbbut it worked! Really, it did!"

(PS: did anyone notice the "No Karma Bonus" checkbox?)