discussion / Acoustics  / 26 April 2024

Acoustically Transparent Epoxy

Hello all,

I'm developing an animal-borne passive acoustic monitoring system and plan to pot the internal electronics in the housing with epoxy to waterproof the system. We're looking into both ECM and MEMS for the microphone. However, a MEMS becomes difficult when potting in epoxy because it would be directly mounted to the PCB and therefore the measured sound would attenuate through the epoxy. It's not a problem with ECM because the mic is not board mounted and can be external. I'm wondering if anyone has any thoughts on acoustically transparent epoxy that could be used for potting a PCB with a MEMS mic with no (or little) sound attenuation? I've made hydrophones with the same concept, by using an epoxy that was acoustically transparent in seawater, but not for airborne acoustics.



Robin Sandfort
@capreolus  | he/him
Capreolus e.U.
wildlife biologist with capreolus.at
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Sounds interesting. 
We all used acoustic membranes.
Just like @BrettMargoSupplies suggested.
A friend of mine had really bad results with animal borne
mics where the pcb was potted and the mic was just covered by a thin layer of epoxy where it hit the surface.
That was not working good!

Greetings from thhe woods,