This is just an introductory question to see if there is anyone in the community that has heard of or worked with Electroactive polymers.
For those who don't know, this is a type of material that reacts "similar" to an esl. If you apply a couple kV to the material, it will shrink, and removing the voltage causes it to go back to its original form. (some can do up to 380% expansion of the materials original size)
If anyone is familiar with this stuff, I would like to start a thread about its possibility of replacing the ESL speaker technology. Otherwise, I won't fill up your forums.
Thanks
For those who don't know, this is a type of material that reacts "similar" to an esl. If you apply a couple kV to the material, it will shrink, and removing the voltage causes it to go back to its original form. (some can do up to 380% expansion of the materials original size)
If anyone is familiar with this stuff, I would like to start a thread about its possibility of replacing the ESL speaker technology. Otherwise, I won't fill up your forums.
Thanks
Damn... that's like 3 speeling mistakes in as many days...
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
I will not argue principles with my principal.
This stuff is hard to find information about since it is still in its research stage. As far as its responce time, NuSil's CF19-2186 has had a responce time of over 100kHz, so the frequency requirements are there. When you look at electroactive polymers (EAP), only look at the dielectric elastomers (DEAP) since they have the best chance of use. Yes, it is used as an artificial muscle, but I am looking into replaceing the subwoofer with this stuff.
Most of the information that I have was bought from online journals, but I do have a few links to help you out.
Here is a detailed description to show you what an EAP is all about.
To sum it all up, take the diaphragm out of an esl and replace it with a DEAP. Instead of going back and forth, the DEAP will expand and contract depending on the voltage (but keeps the same volume, so contracting on the x-y plane will cause expansion in the z-plane.)
This is the first time that I have looked into ESL's so far, so I am not experianced with it. I need to get a power supply that can provide 5 kV with 400 V ac (or so) at 60 hz (low amperage), but I'm not sure if an ESL driver would be up for it.
So, 2 questions for anyone with a few moments:
1. Where could I get a supply that provides this (i have seen 1.5 kv, but not much more)
2. How would you design this for a subwoofer? OR
If you could take an esl and freely form it to your specifications, what would you do?
I have had a few ideas about #2, ranging from attaching a paper cone to the side of the EAP and let the material act as a driver, to creating the cone AND the base out of the eap, or just using the expanding properties to force the DEAP into a bubble shape (forcing an xy expansion without letting it move in the xy, forcing a bubble in the middle).
If you are willing to help, #1 is my bigger problem at the moment, and any other information is helpful. If you have any questions, i will be willing to answer any and all questions (to the best of my knowledge).
Thanks
Dan
Most of the information that I have was bought from online journals, but I do have a few links to help you out.
Here is a detailed description to show you what an EAP is all about.
To sum it all up, take the diaphragm out of an esl and replace it with a DEAP. Instead of going back and forth, the DEAP will expand and contract depending on the voltage (but keeps the same volume, so contracting on the x-y plane will cause expansion in the z-plane.)
This is the first time that I have looked into ESL's so far, so I am not experianced with it. I need to get a power supply that can provide 5 kV with 400 V ac (or so) at 60 hz (low amperage), but I'm not sure if an ESL driver would be up for it.
So, 2 questions for anyone with a few moments:
1. Where could I get a supply that provides this (i have seen 1.5 kv, but not much more)
2. How would you design this for a subwoofer? OR
If you could take an esl and freely form it to your specifications, what would you do?
I have had a few ideas about #2, ranging from attaching a paper cone to the side of the EAP and let the material act as a driver, to creating the cone AND the base out of the eap, or just using the expanding properties to force the DEAP into a bubble shape (forcing an xy expansion without letting it move in the xy, forcing a bubble in the middle).
If you are willing to help, #1 is my bigger problem at the moment, and any other information is helpful. If you have any questions, i will be willing to answer any and all questions (to the best of my knowledge).
Thanks
Dan
So I have done a bit more research, and I did find out how to make the 5 kV supply, but I haven't found how to vary this voltage between, say 3 kV and 5 kV. Could this be done by varying the number of windings on the transformer?
I have also looked at ESL's a bit more, and I need to clarify some details. The DEAP does not need a bias voltage on it, and the walls need to have direct contact with the material, usually using a conductive grease. So, instead of needing 3 connections, I only need 2.
I have also looked at ESL's a bit more, and I need to clarify some details. The DEAP does not need a bias voltage on it, and the walls need to have direct contact with the material, usually using a conductive grease. So, instead of needing 3 connections, I only need 2.
On the contrary, Richard Heydt showed that a 10cm (4 in) EAP loudspeaker could produce 75 db at 10 kH using only 2 kV dc and 400 V ac.
("Sound Radiation Properties of Dielectric elastomer electroactive polymer loudspeakers", H. Richard, R. Kornbluh, J. Eckerle, R. Pelrine. SRI International)
So it is possible to do sound reproduction with DEAP. Granted, it will not be worthwhile at 100 kHz, but this is why I want to do high displacement at 60 hz.
("Sound Radiation Properties of Dielectric elastomer electroactive polymer loudspeakers", H. Richard, R. Kornbluh, J. Eckerle, R. Pelrine. SRI International)
So it is possible to do sound reproduction with DEAP. Granted, it will not be worthwhile at 100 kHz, but this is why I want to do high displacement at 60 hz.
"EAP" is too broad to know what exactly anyone is talking about
the Japanese sold speakers with "high polymer" tweeter that used PVDF "piezo" film - linear strain relation < 10e-3 max
Gallo briefly experimented with reviving the technology before discovering looks sell much better than tech
[it looks like they may still be using pvdf trasnducers: http://www.anthonygallo.co.uk/gallo-story/history-technology3.php ]
there is a new "giant electrostriction" material using similar polymers with irradiation to modify the material to become a nonlinear "relaxor ferroelectric" that have achieved % strains - at high response speeds
the elastomer based electrostriction does seem to face a much lower bandwidth limit since it is partially determined by material stiffness - which in these materials must be deliberately low to get the electrostrictive effect
all really high strain approaches are likely to have problems with electrodes - metallization just won't survive
the Japanese sold speakers with "high polymer" tweeter that used PVDF "piezo" film - linear strain relation < 10e-3 max
Gallo briefly experimented with reviving the technology before discovering looks sell much better than tech
[it looks like they may still be using pvdf trasnducers: http://www.anthonygallo.co.uk/gallo-story/history-technology3.php ]
there is a new "giant electrostriction" material using similar polymers with irradiation to modify the material to become a nonlinear "relaxor ferroelectric" that have achieved % strains - at high response speeds
the elastomer based electrostriction does seem to face a much lower bandwidth limit since it is partially determined by material stiffness - which in these materials must be deliberately low to get the electrostrictive effect
all really high strain approaches are likely to have problems with electrodes - metallization just won't survive
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