More on Micro Turbines

goku writes "Nice article here on the development of micro mechanical turbines." We had an older story about mini-turbines as well.

Comments

Re:Application to notebooks

[danamania]

My immediate thoughts when it came to notebooks, was cooling. Liquid cooling is fine for a big box when it needs half-inch-thick hoses and massive blocks. If small channels around a cpu/heatsink... or even further such as the chassis of the notebook were available to pump fluids, even in small amounts if it were pushed fast enough, a decent cooling effect could occur

Obviously there's some level of heat generated by these turbines, but they may not have to be located anywhere near existing heat sources

a grrl & her server

Heat?

[mmarlett]

The article mentioned noise, emissions and vibration as reasons it might not be popular in cell phones and such, but it didn't say anything about heat. Sure, at a 50% efficiency over the 20-30% efficiency of large turbines they would produce less waste heat (proportionately), but would our little friends get hot?

It ain't going to happen soon.

[enkidu]

I usually expect better reporting from the Economist. This is the kind of breathless "This is great! Here's what all the believers have to say!", I expect from "People" or "Popular Mechanics". Here are some of the problems I see with this wonder battery/generator.

• Operating life. Now, I'm no scientist, but I do know that silicon and high temperatures don't get along too well. But, you could side step that by using similar manufacturing technologies with other materials. Not that I can think of any candidates...
• A turbine does not a generator make. Show me the electricity! Silicon ain't magnetic people. OK, magnetless generators exist, how about "coils" then? Show me the coils! Until I see a working, efficient, microsized generator, I don't see any of this happening.
• Call me a crotchety old man, but I just don't buy the efficiency numbers I'm seeing. As things get smaller and smaller, your perceived viscosity goes up and up. Same design + smaller size = less fluidic efficiency. Same goes for the friction + mass problem. Combustion efficiency will probably go up since it's easier to model with the small size.

This leads me to my problems with the nano-technologists we have nowadays. Where's the power? Anybody have a 1 cubic milimeter battery that'll last 1 hour yet? Show me a self powered nanobot. Hell, show me a nano-power source that works! Remember, volume decreases by the cube as you scale down. Sure a quintillion nano-bots could make me breakfast out of yesterday's trash, but what's going to power them? You can't get out more than you put in, you know. Reminds me of the great Larry Niven's quote: "Another beautiful theory, murdered by a gang of ugly facts."

I don't see this stuff (nano-technology, micro-turbines) panning out any time soon (Now, bio+nano or plain bio, I can see scaling down. Also, mini-turbines (1-10 cubic centimeters) I can see happening also.

EnkiduEOT

Re:It ain't going to happen soon.

[foniksonik]

Just gotta say this one thing:

Bumblebees by macrophysical limitations should not physically be able to fly!

Things work differently at the (physical)level these people are working at. Give them at least a little credit for spending the time to research and analyze. Surely they would not be publicizing this info without a minimum of verifiable evidence.

All of your 'evidence' is based on macrophysics and common knowledge. Microphysics and especially that which deals with physics at the molecular level is much different and obeys radically different laws.

For example, viscosity: rarely does viscosity play any and I mean any role at a microscopic level... otherwise nothing would work... can you imagine molecules behaving according to 'viscosity' instead of various types of polarization or attraction to other molecules... I think not.

Viscosity is definitely a macroscopic topic and plays absolutely no part in MEMs research... now valence levels and atomic/molecular attraction may be relevant.

Re:It ain't going to happen soon.

[MarkusQ]

I'm no scientist, but I do know that silicon and high temperatures don't get along too well.

The problem is with mostly doped silicon; at high temperatures the dopants tend to migrate, which is bad for very small, very fast electronics. It isn't a mechanical problem.

This leads me to my problems with the nano-technologists we have nowadays. Where's the power? Anybody have a 1 cubic milimeter battery that'll last 1 hour yet? Show me a self powered nanobot. Hell, show me a nano-power source that works!

Sure, if you show me a car that drills its own oil and refines its own fuel from it. Where'd you get the "self powered" requirement? All they need to do for most applications is receive power (e.g. from high frequency sound waves) and convert it to mechanical energy. For the sound waves--which look like pressure waves at that scale--all you need is a piston.

Remember, volume decreases by the cube as you scale down.

False logic. The power requierments also scale down, sometimes by as much as the fifth power IIRC.

Sure a quintillion nano-bots could make me breakfast out of yesterday's trash, but what's going to power them?

How about yesterday's trash? 1) it's there, and 2) there's plenty of it, so 3) you aren't going to use all of it, and 4) part of what you don't use would burn, so 5) controlled, small scale oxydation (e.g., what microbes, fungi, etc. would do if they were converting the trash) should give you all the energy you need.

Heck, if you're building a diamondoid structure of some sort instead of just cooking breakfast for a skeptic, you'e have way more reduced hydrogen than you need, so just use that and dump the resulting water.

-- MarkusQ

Why?

[gerardrj]

Micro turbines on soldiers? First time they dove in the dirt, got wet, or accidentally covered the air intake, the thing would stop. Can you imagine how small the string must be that you wind around it to spin it back up?

I also must ponder this: If you're thinking about putting a fuel like Hydrogen on the soldier, why not simply put a small fuel cell on them instead. It has NO moving parts, is quite efficient today, requires no new research, and works in any orientation as long as it gets air.

This seems like a solution in search of a problem and funding.