Technology to absorb Electromagnetic Field energy

Thread Starter

uon

Joined May 1, 2007
5
Apologies if I am ill informed on a lot of the physics side of things.

Firstly hi to all...:)

Got recommended to these forums by my gf. My name's Eugene and am an Industrial Design student in Sydney, Australia. Am currently finishing up a project for sustainability through a product. Was wondering...does anyone here have any information on technology that absorbs electromagnetic field energy...ie from other electrical appliances??? Can energy from electromagnetic fields given off by appliances be absorbed and redistributed/re-used???

I needed to know if the design of my product will be feasible so that I can explain what is going on. I have conceptual ideas, now I need backup information. Thanks in advance.
 

thingmaker3

Joined May 16, 2005
5,084
Some hobbyists and university researchers will use graphite crucibles to absorb microwaves for heating metal and/or ore. IIRC it works because of random orientation of the graphite flakes in the clay mix. Ordinary kitchen type microwave ovens are used by the hobbyists. The researchers modify the kitchen type ovens - in one case six magnetrons were ganged together for smelting steel from ore.
 

Salgat

Joined Dec 23, 2006
221
Well he wants to re-use it. Photons come in a large diversity, I'm pretty sure you have to first choose a range before you can start working to absorb the electromagnetic forces.
 

Dave

Joined Nov 17, 2003
6,970
Well he wants to re-use it. Photons come in a large diversity, I'm pretty sure you have to first choose a range before you can start working to absorb the electromagnetic forces.
This is very true. Dependant on the frequnecy you are looking at will dictate the absorption mechanism.

Dave
 

Thread Starter

uon

Joined May 1, 2007
5
cool...thanks so much for the replies guys and gals...

ok ok...here're some criteria...the electromagnetic forces i'm trying to absorb will be coming from common appliances you find around a typical bedroom...eg, ceiling lights, laptops, computers, desk lights, clock etc...

will the range of frequencies for these appliances be generally around the same vicinity??? or is the range too wide and i should really concentrate on a more specific range???

plus, does anyone have any links or info on how much electromagnetic force different appliances emit???

thank you so much...greatly appreciated

P.S the water idea sounds promising...like...this doesnt HAVE to be technology, like the simpler the absortion and conversion mechanism, the better...:)

P.S.S some links to papers on this subject would be great too...so that i can reference studies and info on the matter...like i said, i'm not a physicist, just a designer...:)
 

kubeek

Joined Sep 20, 2005
5,726
My guess is that the total energy around is in the range of mili-watts, but surely less than one watt.

And this is just the raw energy that is out there. The efficiency of using it will be very low even with a complex design.

What sort of device are you thinking about to power?
 

nomurphy

Joined Aug 8, 2005
567
Sure you can, but just realize that any energy that you "absorb" will be seen as a "drain" by your electric company and thus turn up on your monthly bill.

(Most appliances are 50-60 Hz.)
 

Salgat

Joined Dec 23, 2006
221
I just want to state that what your asking for sounds incredibly impracticle. Whatever EMF that might leak from your common appliances is probably extremely low, and would probably just be an additional load on the circuit. Thats my opinion on it.
 

Dave

Joined Nov 17, 2003
6,970
To me the problem is converting the absorbed energy into something useful. RF and microwave field absorption generally dissipates the energy in a dielectric object (typ. water based) as heat - where do you go from there?

Dave
 

Thread Starter

uon

Joined May 1, 2007
5
My guess is that the total energy around is in the range of mili-watts, but surely less than one watt.

And this is just the raw energy that is out there. The efficiency of using it will be very low even with a complex design.

What sort of device are you thinking about to power?
Wasnt powering a particular device...was gonna rechannel this energy into an induction charging plate for portable devices...
 

goodbyegti

Joined Apr 28, 2004
59
plus, does anyone have any links or info on how much electromagnetic force different appliances emit???
The force on an object due to EM radiation is given by Poyntings theorem:

In a nutshell:

Force = (N x Area) / (speed of light)

Where N is the power per square metre.

For example, assuming a 100W lightbulb is 10% efficient the force per square metre exerted on a black object a distance 1m away is:

[ (100W x 0.10) / (4 x pi) ] / (3 x 10^8) = 2.7 x 10^-9

For a perfectly reflecting object the force will double but in any case it's tiny!
 

leberk

Joined May 5, 2007
7
Well if you use a high impedance DC voltmeter with neg cxn to good gnd and pos in your hand you will read about +.1 volt. No doubt that can be stored in a capacitor. Multiple capacitors should multiply the energy stored. Right?
 

bloguetronica

Joined Apr 27, 2007
1,372
Well, as I said. I recommend an iron box to "sink" all the electromagnetic waves.

Like Thomas Andrews said: "She is made of iron Sir! I assure you she can sink!"
Dark humor. LOL:D
 

thingmaker3

Joined May 16, 2005
5,084
Well if you use a high impedance DC voltmeter with neg cxn to good gnd and pos in your hand you will read about +.1 volt. No doubt that can be stored in a capacitor. Multiple capacitors should multiply the energy stored. Right?
Just hook up hundreds of thousands of humans in series-parallele and you can... waitaminute, some guys with suits and dark glasses are at my door. I'll be right back.
 

Thread Starter

uon

Joined May 1, 2007
5
Wasnt powering a particular device...was gonna rechannel this energy into an induction charging plate for portable devices...
yeah...was gonna rechannel the energy if possible...can this be done then in favour of storing it???
 
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