Matching Layer Material for Air-Coupling @ 200-500 kHz
I am looking for a matching layer material to air-couple piezo sensors at 300kHz (or 200-500 kHz).
I have been using the MA400A1 Murata sensors so far, but their 1.1cm diameter is too big for my application, and that is why I am building my own. These Muratas have a thick (~1.5mm) white porous material at the front.
Does someone know what type of material it could be?
I have been looking for different filtration membranes (polyetersulfone, cellulose, etc) to use as matching layers, but most of them are too thin to work with (~100 um).