Method for making thermoacoustic device

A method for making thermoacoustic device, the method comprising:

• providing a silicon substrate having a first surface and second surface that is opposite to the first surface;
• patterning the first surface to form a patterned surface comprising a plurality of bulges substantially oriented along a first direction, wherein the plurality of bulges is spaced from each other, and a groove is defined between each adjacent two of the plurality of bulges, and a depth of the groove ranges from about 100 micrometers to about 200 micrometers;
• coating an insulating layer on the patterned surface;
• applying a carbon nanotube structure on the patterned surface, wherein the carbon nanotube structure is suspended above the groove;
• and
• locating a plurality of first electrodes and a plurality of second electrodes on the plurality of bulges and electrically connected to the carbon nanotube structure, wherein the plurality of first electrodes are spaced from the plurality of second electrodes.