I found a German patent from Michael Jennsen DE 199 42 739 A1. He uses piezzo ceramic rings with a diameter less than 0,1mm and a membrane out of noble metal. Driven by ambient temperature the gas pressure is quickly changing at the small membrane. A rectifier is used to transform the chaotic alternating current into usable direct current. At this point I fear that the voltage of the small piezzo elements is to low to overcome the threshold voltage of a normal rectifier. Has any one experience with this invention?
Thanks in advance
Andreas
As long the voltage generated by the piezo-electric element is greater than 0.6 volts the
rectifier will conduct current. Here is a neat trick that I use to demonstrate the piezo-electric
effect: take a piezo-electric buzzer element (the kind that are round brass disks) and connect
a LED to the two leads of the element. When the piezo disk is tapped (I use the eraser end
of a pencil) the LED will flash.
Take care.
I imagined using nanometer scale speaker coils and magnetic slugs or pizeoelectric elements feeding bridge rectifiers to make a strong challenge to? 2LT, the widely accepted law leading to the Grey Death of the Universe, then I pared down the design to the rectifiers. To continue the persuasion, we need to optimize the geometry of the conceptual piezoelectric device to deliver a high voltage under Brownian impacts. One approach, imaginary parts costing nothing, is to use transformers. The pizeoelectric device / transformer (Brownian, mrechanical) can be replaced by a high value resistor (Johnson, electronic).? ?
Aloha, Charlie
Another transducer is the elctret microphone. Electrets are permenently electrostatically polarized materials.
Going in a new direction, imagine nanoscale pillars of polarized electret material inside a diode bridging the junction. Perhaps that would bias a diode for small signal work. This has been in my idea closet for years. Thanks for letting me be comfortable enough to share it.
Aloha, Charlie
Hi Charlie,
the idea using an electret for bridging the threshold voltage of a diode is great. May I take the liberty of awarding you my private Nobel prize ;D
But there is already the next question, do you have any idea whether it is possible to miniaturize an electret down to some nanometers by retaining a voltage of about 0,5V? :'(
Regards
Andreas
Interesting.....supposedly the Kowsky-Frost discovery was made while studying the PE effect....using, I believe, microphone piezos.
http://www.keelynet.com/gravity/KFrost.htm
http://www.main.org/polycosmos/gravhack/gravity.htm
http://www.rense.com/general54/babalc.htm
I find it interesting the Quartz and Gold are almost always found together in nature.
Peace,
TS out
I slogged through google to get an idea of electret voltage and got 1/10 V / micrometer. This is not a solid number. Only a little boosting in the lowering the barrier voltage is possible because the increased conductivity of the junction reduces the effect of the electret. Electret embedding of the opposite polarity may be useful in thernovoltaic cells to help pull the electron / hole pairs apart and reduce their premature recombining .
Aloha, Charlie
yes this idea was also in my "idea closet" for years... I thought of some ways to use piezos as diaphragms to make the motion less chaotic, so that it pulses many of these micro piezos at once...
my e-mail address is: a m m e n a r d @ u h . e d u
This has been my think hole for this past semester, and I am anxious to hear some more of the ideas you have.
Andrew Menard
Even if It gives only .1 V, that is a 33% reduction in GaAs Diodes, bringing the threshold voltage down to .2V if I am not mistaken. Not neseccarily something to be abandoned.
The pillars can be longer, first coated with an insulator, then a conductive sleeve folded back and covered with another insulator to give a higher voltage at the gap filled with the semiconductor. Maybe the structure is so large that one complex pillar surrounded by annular semiconductor would be used. This is ugly but perhaps interesting.
Maybe deep oppositely charged doping where trapped ions would polarize the lattice behind the active dopants would do the same thing if the mobile charge carrier partners involved can be induced to work in a desirable way.
Can advanced devices be based on InSb?
Aloha, Charlie
What about the U of Chicago's discovery of negative resistance displayed in crossed carbon polymers? Could that somehow be used to reduce the diode bias voltage?
My first response to googleing: crossed carbon polymers negative resistance was http://wings.buffalo.edu/academic/department/eng/mae/cmrl/Apparent%20negative%20electrical%20resistance%20in%20carbon%20fiber%20composites.pdf I heard that PDFs were hard on some people's browsers so proceed accordingly. The negative resistance was carefully called apparent rather than true even though with regression analysis ~whatever~ it graphed through 00 , the orgin and was of negative slope. Current going through it heated it, a strong point for realistic evaluation. It had low resistance in AC circuits to MHz frequencies. Semiconductor properties were mentioned. It is an offering of the new discipline of structual electronics. I am curious about the materials use as an electroplating cathode.
Aloha, Charlie
I have found some schottky diodes with Vf=375mV made by Agilent...they are quite expensive, but they are quite low threshold voltage.
added minutes later...
from Agilent's website
"The HSCH-534x family of low barrier Beam Lead Schottky diodes are ideally suited for mixer and detector applications from 1-26GHz. These products are suitable for applications that require guaranteed RF tested performance. Vbr=4V. Max. (Vf)=375mV. Max leakage Current (Ir)=400nA. "
I don't exactly understand why higher voltage generating piezos cannot be used. I can only understand this in an OPEN AIR situation where at ambient pressure and temperature there is a maximum pressure which can be exerted on such a piezo, thus limiting voltage....But if you have a container with the piezo enclosed with larger voltage, you should be able to 'tune' the pressure in the closed container to where the piezo has just enough pressure on it where it is in disequilibrium causing it to push in and out, NOT just push in and stay in. Please forgive me if I forget something completely obvious, as I am not an expert in piezoelectrics.
I have done some basic piezo work. The voltage is produced by a change in shape. The pressure in a chamber exerts its force universally on the material, so while the pressure is increasing the material compresses. But it won't decompress unless the pressure is relieved. So you end up with a direct correlation of votage proportional to the change in shape wich is proportional with the change in pressure. You would have to oscilate the pressure to get a continuous voltage out. Otherwise you get a voltage while you set the pressure, but then the material settles at equilibrium with its new environment and voltage drops.
If I am wrong, either in my assesment of the material or that of your idea, please let me know. I am always ready to learn something new.
Hi Kysmett,
the idea of the patent was to use very small piezzo elements with only some hundred nanometers. Than the local pressure variations should be strong enough to generate a constant current. If you try to rebuild this effect within a larger scale the classical laws of thermodynamics are valid and nothing will happen. Only if you go down to nanometers you can utilize the kinetic theory of gases. And this is exactly the problem for non industrial research - we don't have the possibilities to proof our own theories.
Best regards
Andreas
I wonder how one would structure the material...I say material because I see the end product somewhat like velvet. A flexible fabric sub-structure with tiny, piezo nano hairs on it. If worn, or flown from a flagpole, you would get more than just ambiant prssure flux....hmmmm... will have to cook on this some more. Textile manufacture seems to play a large part in my mental picture however. The remaining question lies thus: How dificult would it prove to actually make (or grow) some of this stuff on a fabric?
The Michael Jennsen patent is available to view on the following link
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=DE19942739&F=0
If there is any trouble downloading it I could post the PDF version.
Hi Kysmett,
the idea of a velvet like piezo structure sounds very reasonable. But even if you can produce such a material, the next problem is to rectify the alternating voltage. Maybe it is possible to combine piezo hairs with nanotubes that work like an diode. GE is leading in developing such devices http://www.azonano.com/details.asp?articleID=996. Maybe there are also other companies who see a chance in surpassing GEs success with this new idea of combining piezo hairs with nanotubes.
Reagards
Andreas
The little cells descibed in the patent are evacuated, to make one dimensional pressure, and sealed with an ultrathin membrane. I would think they would only work for a limited spectrum of pressure and gases.
well we know pV=nRT at this 'classical' level. Pressure is dependent on the number of molecules and temperature and independent of the individual molecules size. The heavier the gas we use surrounding the piezo, the slower the gas molecules will travel, communing the same amount of kinetic energy to the walls per second. If we use heavy molecules which are gaseous at room temperature, z.B. Halon gas: Dibromotetrafluoroethane Atomic weight: 259.84, the average velocity of the gas particles is reduced by about three fourths. Lower velocity particles means more time for the piezo to relax back into its resting position, meaning you can use a little larger piezo. Furthermore, if giving the piezo time to relax is an issue, just put fewer molecules surrounding the cells, just enough pressure to push in the piezo.
There are other less reactive refrigerants which could be used, but if you want stability perhaps xenon tetrafluoride, but thats not a household ingredient like refrigerants.
In case you're wondering where I got that three-fourths figure, I used:
1/2*m1*v1^2=1/2*m2*v2^2 to get
v1=v2*(m2/m1)^(1/2)
try m2=16 (oxygen), m1=260(Dibromotetrafluoroethane), v1=.25*v2
Regards,
Andrew
Using the piezo design guide from piezo-kinetics, http://www.piezo-kinetics.com/Catalog_pages_15-26.pdf, I calculated the patent's piezo with an outer diameter of .1mm and inner diameter of .033mm to produce on average 121mV in standard temperature and pressure, assuming that the foil diaphragm allows the strike area to be the full diameter of the piezo, .1mm. I didn't see how the foil extending outward from the outer diameter of the piezo to the flush ceramic base could help produce a force, since it would be bending in this area, negating pressure force. I can see why the inventor had trouble getting substantial voltages, when using a steel foil as the diaphragm. Mechanical stress could oppose some of the pressure force.
high guys, i found -years before-the patentschrift dd287597.
for global interests-i,for myself think it-could be the dd286012
similar to the solar-cycle(carl friedrich von Weizsaecker,club of rome)
but "fuer die friedliche Nutzung" of the surrounded ambient energy
without great costs and sustainable.
Look also at "Piezoelectric energy" http://www.overunity.com/index.php/topic,121.0.html. There are also some interesting information listed.
Regards
Andreas Varesi
what is,without words,in a real tridimensional explanation "piezo-electric"?
The reverse mode of the liquid iron demonstration(Don Adsitt),material stress noise?
thermovoltaic=thermalnoise
thermic=motion,maxwell/boltzmann;
Hello to all,
Look at the patent #413,353 of Tesla.
Simple method to rectify the AC to DC current using a modified transformer.
Wiegand wires or similar bistable magnetic elements and permeate magnets would be better, as it is easy to get 5 volt pulses.
George King
georgeking@cosmicsalamander.com
Perhaps you will find this article interesting(attached pdf) . It was published in Wireless World late 80's or early 90's. I called Pennwalt to see if John Scott Strachan still worked there when I was director of research and development at another company during that period. They said he no longer worked there and had no record of how he might be contacted. They were kind enough to send me some samples of the piezofilm. I have not performed any of Strachan's experiments although this method, if it works, would be ripe for development. The magazine chose to place the words "Hypothesis" at the top of each page, I suppose as a disclaimer. John Scott Strachan has several patents. For this google CA 2003318 patent application.
Best of Luck in your research.........V