Thermoacoustic excitation of sonar projector plates by free-standing carbon nanotube sheets

Carbon nanotubes (CNT) generate smooth-spectra sound over a wide frequency range (1–105 Hz) by means of thermoacoustics (TA). The protective encapsulation of CNT sheets in inert gases between rigid vibrating plates provides resonant features in the TA sound projector. The vibrational modes of plates and the compliance of the soft sealing spacers between those plates are studied with the aim of creating efficient, tunable underwater sound generation at relatively low frequencies, 10 Hz–10 kHz.