Do ultrasonic sensors sense through transparent materials?
I'm assuming you mean a "normal" sensor, like this:



Ultrasonic sensors work by sending out sound waves. Obviously, sound waves don't care whether a material is transparent or opaque, so they are blocked just as easily by acrylic as by a brick wall.

Side note: If you look on the front of an ultrasonic sensor, you will notice that it is covered by a screen, not glass or plastic. This is why.