Piezoelectrically actuated diamond cantilevers for high-frequency applications

In this work, we present a proof-of-concept for the modulation of field emission currents from boron doped nano-diamond based micro-electro-mechanical cantilevers. This modulation was achieved by variations in anode-cathode spacing using mechanical oscillations of the field emitting tips by means of piezoelectric actuation of an aluminum nitride layer. In these devices, the nano-diamond layers serve as a multifunctional material as they are used as field emitters, elastic layers in a unimorph layer stack and as electrodes for piezo-actuation. The cantilevers are processed using conventional micro-fabrication technology and are enhanced by focused ion beam milling, introducing nano-scale features. In addition, it is shown that a stress compensating geometry is efficient to counteract the large thermally induced strain in the nano-materials used.