A 1.6 GHz NEMS actuator built from carbon nanotube layer by layer composite films

MEMS or NEMS devices have been studied as a candidate to substitute for CMOS devices because of their ability to have off-state currents much less than 1 pA [1]. This is a particularly compelling attribute when one compares them to deeply scaled CMOS. However, MEMS devices have not shown high speed switching capability [2]. Indeed, there is an inherent tradeoff in cantilever design between frequency of operation and pull-in voltage. Thus, there have been no reports of switching a fabricated cantilever at speeds less than 1 μsec with pull-in voltages of a few volts or less. A careful investigation of the device parameters governing cantilever operation suggests that the way to make high speed devices with low pull-in voltages is to use extremely small gaps and light weight materials. Therefore cantilevers were made from an aligned composite single wall carbon nanotube membrane was prepared by a dielectrophoretic self-assembly process (AC-SWNT). The process, as detailed in our recent report [3] uses alternating layers of aligned carbon nanotubes and polymer. The fixed-beam switch consists of a gate electrode and a 20 nm thick AC-SWNT membrane suspended between two electrodes.