摘要 |
<p>An apparatus (200) comprising: a first electrode (204), wherein the first electrode comprises at least one layer of graphene; a second electrode (208); and a layer of piezoelectric material (206) disposed between the first electrode (204) and the second electrode (208), wherein the piezoelectric material (206) is able to resonate at a resonant frequency in response to application of an oscillating electrical signal to the first or second electrode (204, 208).</p> |