PVDF and you - (01)

[brian carroll]

so i have been researching PVDF piezo film sensors
via a technical manual [0] and there is a lot here that
may be of potential interest in terms of its applications,
[1] especially its use in security systems and to prevent
tampering, and energy harvesting, in addition to other
areas where its unique functionality could be explored.

what follows, a series of short posts about this material...


0a. Measurement Specialties PVDF technical manual (PDF)
http://contactmicrophones.com/techman.pdf

0b. technical manual with Appendix of piezo film articles
http://www.tufts.edu/programs/mma/emid/piezo.pdf

1. Measurement Specialties Piezo Film Product Guide
http://www.meas-spec.com/downloads/Piezo_Film_Product_Guide.pdf

---

so PVDF is 'piezo film' that has unique properties and
capabilities. while i know little of functional electronics,
it is said to be a capacitor that stores and discharges
high voltage energy. like a piezo disk it picks up the
vibrational energy due to structural deformation that
then generates or moves charge in response to this.

the application i recently first encountered it was with
'contact microphones' - where it was stated that these
PVDF film tab mics record the vibrations as sound input
rather than acoustic pressure of condenser and dynamic
capsule microphones reliant on soundwaves moving the air.

so the distinction is that this piezo film can function as
a recording input or SENSOR though by registering the
vibrations on the surface of a material. what is more, it
also detects temperature differences and thus can be
employed as a sensor this way as well, which i did not
realize was possible nor expect for a 'microphone'.

the PVDF film apparently is already used in security
applications within computers, if not crypto systems
protected from tampering, via vibration sensing that
triggers lock down or equipment destruction based
upon monitoring of piezo film signals at perimeter.

PVDF film for Tamper-Proofing, Security (white paper)
http://www.meas-spec.com/downloads/Applying_Piezoelectric_Film_in_Electronic_Designs.pdf

(interesting likewise is use of piezo coaxial cable for
perimeter security, strung on fencing as a microphone
and also buried underground, which then can register &
record raindrops, footsteps, people climbing fence, etc.)

to be continued: ideas and observations about PVDF...


spatter glass, azimuth circle, rift zone