Modeling a carbon-nanotube-based nanoelectromechanical relay
We have theoretically investigated the properties of a three-terminal
carbon-nanotube-based nanoelectromechanical relay. The system operation
is based on an coupling between electrical and mechanical degrees of
freedom which is a typical characteristic of a NEMS device. Another
is the small size of the system which typically is in the nanometer range.
This small length scale and the extraordinary stiffness of carbon nanotubes
imply that the intrinsic mechanical frequency of the system is
in the GHz-range. We show that operation of the device as a switch
in this frequency regime is feasible due to dissipative processes
associated with tube-drain electrode interactions. Furthermore, the
system responds resonantly to a narrow band of GHz-frequencies and
the main resonance can be tuned by changing bias voltages. The effect
of electromagnetic fields with frequencies in the resonance regime
is also investigated, but, extraordinarily high field strengths
are needed to affect the system.
The influence of surface forces is calculated, and, they
are shown to introduce design constraints to avoid the
ubiquitous ``stiction problem'' in nano science. This problem can be
alleviated by changing the design into one that relies on
field emission charge transfer. This non-contact-mode design complements the
former contact mode device, its properties are investigated, and we observe
a qualitatively different behavior compared to the original design.
high frequency applications