An acoustic or vibration sensor particularly useful in detecting nano-vibrations includes a body 40 having a generally C-shaped cross-sectional configuration. A base 44 is positioned within the body 40 and has at least one protrusion 68 extending from the base 44 intermediate end portions 48 of the C-shaped cross-section. A film 14 extends about the base 44 and over the protrusion 68 to form a space between a portion of the base 44 and the film 14. The film 14 is engaged with the end portions 48 of the C-shaped cross-section and urged at least partially into the space to place a desired tension on the film.