'(OT) Piezo Kynar - PVDF Film'
Lance and others,
Half of my time till July is being absorbed in using Kynar film to measure
peel stresses in adhesive joints.
>The problem was the generation of usable power did
>require quite a bit of flexing of the generator and it was
>more appropriate to generate a charge over some time
>and then burst power some sort of device.
>It would be fun to get funding to pursue that sort of line
>though, I can see applications like emergency devices
>etc that might be stored for years where maybe a
Funding runs out then but I have in mind to attempt to generate the
requisite power to exception log and report events with the same material,
as Lance says it is ideal for such purposes.
Glen Torr (No relation to Rolf Harris)
Australian Defence Force Academy
School of Aerospace and Mechanical Engineering.
This message was sent through MyMail http://www.mymail.com.au
Martin G. McCormick
I gather from the subject that this film has piezoelectric
properties, but what is it like to use? How large are the pieces that
one can get and how are they energized?
I am not exactly sure of the correct way to word this
question, but is it possible to energize parts of the film without
emergizing the whole piece? I am thinking of a matrix in which
one could break the surface in to cells and either generate movement
or read the position of movement based upon which coordinates were
Martin McCormick WB5AGZ Stillwater, OK
OSU Center for Computing and Information Services Data Communications Group
I would think that you could use selected areas of the film. One way
would be to remove portions of the metalization that is applied when the
material is manufactured. The metal was silver on the samples I played
with a long time ago. The film itself is Kynar, I think, like wirewrap
In large quantities the manufacturer would probably be willing to screen
your custom pattern onto the film.
The amount of movement is extremely small. It is a fractional thickening
of the film which itself is only a few thousandths of an inch thick.
"Martin G. McCormick" wrote:
> I gather from the subject that this film has piezoelectric
>properties, but what is it like to use? How large are the pieces that
>one can get and how are they energized?
The PVDF film I have been using is 52 micro meters thick and is supplied
metalized all over on both sides with a Cu/Ni layer approx. 250 angstrongs
thick, The PVDF I get comes in sheets approx. 8 inches by 6 inches but I
dare say larger sizes are available. It is also available with a silver ink
conductive coating which is much thicker.
An active area is an area where the PVDF has metalization present on both
sides. To make a sensor the metalization is etched away to form an active
area, the connections to this active area are formed by leaving tracks of
metalization on one side only to connect to the overlapping active area.
I have so far constructed sensors from Ni/Cu coated material using PCB like
techniques except that Ferric Chloride etch time is several seconds only.
I have not yet made multi point sensors though I have seen one described
with 9 sensors 1/10 inch square on a single 1 inch square. Two things to be
noted is the extremley low series capacitance of small sensor/exciters and
the need to route connecting tracks so they dont cross other tracks creating
undesired active areas.
|> I am not exactly sure of the correct way to word this
> question, but is it possible to energize parts of the film without
> emergizing the whole piece? I am thinking of a matrix in which
> one could break the surface in to cells and either generate movement
> or read the position of movement based upon which coordinates were
> being disturbed.
> Martin McCormick WB5AGZ Stillwater, OK
> OSU Center for Computing and Information Services Data Communications Group
The development kit from AMP (back when it was theirs)
suggested applications along those very lines, like
flexible keyboards, baseball pitching targets etc all on the
The biggest hassle would be connecting electrodes to
each cell and I would imagine cross talk might be a
How are they energized you say.
Being Piezo a movement will generate an AC voltage
across the metalised electrodes either side of the PVDF.
There is no bias voltage like with a capacitive sensor.
Uni of Auckland
More... (looser matching)
- Last day of these posts
- In 2000
, 2001 only
- New search...