Coating a piezoelectric transducer...

Bernard

Joined Aug 7, 2008
5,605
I would use several coats of clear Krylon spray, or as I still have a little left. Permalac, spray lacquer which
" We " have used for exterior metal artwork for several years.
I read & thought I had hard copy of how to make an under water microphone, but my search turned up zilch.Will try to recall parts if desired.
 

RichardO

Joined May 4, 2013
2,271
Since the body is mostly water... In my long ago days in diagnostic ultrasound I saw transducers with epoxy, urethane and silicone rubber on the face that contacted the skin.

Also, don't forget the backing material. If the transducer uses a pulse to get an echo then the backing must damp the transducer so it does not ring for too long a period.


Note that these are tidbits I picked up in passing and may or may not have value. ;)
 

Thread Starter

Externet

Joined Nov 29, 2005
1,527
Thanks.
My concern is mostly oriented to discern if a soft or a hard coating, to avoid impairing/blocking/absorbing its vibration response. Seems so far I will go with a thin layer of silicone. Will see...
 

Alec_t

Joined Sep 17, 2013
11,503
To maximise transmission and minimise spurious reflection at interfaces the acoustic impedance of the coating should be intermediate between that of the transducer and that of water. Tables of acoustic impedance for various materials can be found here.
 

hp1729

Joined Nov 23, 2015
2,304
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