FIG. 3.

(Color online) Responses of the membrane/fiber sample when driven with a 7008 Hz pure tone of a level that resulted in a relatively large, but undistorted 200 nm vibration of the membrane [panel (E)]. (A) A-scan indicating the points of evaluation. (B)–(E) Thick red and mid-thickness green curves are, respectively, the reported and theoretical displacement responses. These responses are shown at the locations of the fiber and the membrane (prominent peaks 1 and 4) and two locations in-between. (F) The frequency spectrum corresponding to the displacement of point 3. Noise has been removed for clarity in the thick red curves of panels (B)–(E), by filtering out frequency components that were beneath the noise floor [see red curve in panel (F) for an example of the noise floor and emerging components]. The theoretical displacement curves (green mid-thickness) were found using the A-scan and vibration results from the fiber and membrane, assuming the fiber was stationary and that the membrane moved as reported [represented by dashed and solid thin black lines, respectively, in panels (B)–(E)].