  Nano-electromechanical (NEM) contact switches have been extensively studied
to suppress the limitations of conventional complementary
metal-oxide-semiconductor (CMOS) transistors. The attributes of NEM contact
switches includes reduced power consumption, reduced off-state leakage current,
increased on-state current and sub-thermal switching. However, unacceptably
high pull-in voltage and low contact lifetime posed a significant challenge for
the use of NEM contact switches in energy efficient CMOS applications. Here, we
demonstrate a graphene-based electro-statically actuated NEM contact switches
with ultra-low pull-in voltage and significant improvement in the contact
lifetime. This was achieved by using the graphene on gold electrode as a
contact material. The graphene NEM contact switches with graphene as a contact
material exhibits an ultra-low pull-in voltage of 0.5 V and high contact
lifetime of more than 1.5x10^6 cycles. The switches also showed an excellent
switching performance with high on/off ratio of 10^8, an extremely low
off-state current of 100 fA, and small hysteresis window of 0.1 V.
