Acoustic Electricity Generation - Modern Applications

[WiseGuy01]

I do apologize if this is considered against the general discussion rules. I'd really like to get the opinion of individuals of an intellectual nature. I remember a recent discussion with a few family members on the topic of building infrastructure (roads) that generates electricity utilizing piezoelectric materials via moving traffic. After having reflected on things for some time I ended up with a crudely drawn paint image and a burning question... is there an efficient way to convert and/or store acoustic energy utilizing resonance of ( high density) elastic mass encased within a rigid crystalline housing (high density)?

 

[russ_watters]

Yes, it's a crude drawing, but what you describe is the basic purpose of a microphone. The problem is, there just isn't much sound energy out there, so they only generate a tiny amount of electric power.

 

[Borek]

In other words: just because a place is noisy doesn't mean the noise carries lots of energy.

 

[WiseGuy01]

Yes, it's a crude drawing, but what you describe is the basic purpose of a microphone. The problem is, there just isn't much sound energy out there, so they only generate a tiny amount of electric power.

I was thinking you could use the impact of falling water (terminal velocities) into a folding horn enclosure as the acoustic input, where I'm scratching my head I guess is how do you input acoustic energy into your resonator without loss of energy and how does it remain contained thereafter?

I realize there's not always a lot of energy in sound, that's the whole point of my project... to find out if you can take otherwise useless acoustic energy and turn it into a force you can do work with?

To be clear the resonators purpose is to store and amplify acoustic energy through resonance. Thanks for the replies. Hehe microphone :)

 

[russ_watters]

I was thinking you could use the impact of falling water (terminal velocities)...

We already have that too: it's called a turbine. And they are pretty good as it is (though doing it at terminal velocity is a waste).

...into a folding horn enclosure as the acoustic input, where I'm scratching my head I guess is how do you input acoustic energy into your resonator without loss of energy and how does it remain contained thereafter?

To be honest, this just sounds like technobabble to me. Perhaps I'm just not understanding or it isn't focused enough..

I realize there's not always a lot of energy in sound, that's the whole point of my project... to find out if you can take otherwise useless acoustic energy and turn it into a force you can do work with?

Well, again: yes, just not much.

 

[NTL2009]

https://spectrum.ieee.org/consumer-electronics/gadgets/acoustic-energy-harvesters-gaining-volume

The problem is that acoustic energy is not very dense: The sound of a crowd in full roar at London’s Wembley Stadium would provide only enough energy to fry an egg, Sheplak estimates.

... Sheplak’s team managed to extract about 30 mW in a laboratory experiment by mimicking a jet engine.

So yes, it can be done. But the energy levels are small, and there are significant losses in the capture devices.

But there may still be applications for things like this. Many of our electronics draw very low average power (clocks, remote sensors, for example). It would be convenient to never change a battery. Acoustic energy is just one. I think the changing in atmospheric pressure is interesting, it would seem to be limited only by the area of the diaphragm you could use? More:

https://en.wikipedia.org/wiki/Energy_harvesting
https://en.wikipedia.org/wiki/Atmos_clock

Clocks powered by atmospheric pressure and temperature changes were subsequently developed by Pierre de Rivaz in 1740,[2] and by James Cox and John Joseph Merlin (Cox's timepiece) in the 1760s. The Beverly Clock in Dunedin, New Zealand is still running despite never having been manually wound since its construction in 1865.

And these clocks are not all that large. I had no idea this had been implemented so long ago. Nothing new under the Sun!