  In this article, we introduce a new nanoscale electromechanical device -- a
leaky memcapacitor -- and show that it may be useful for the hardware
implementation of spiking neurons. The leaky memcapacitor is a movable-plate
capacitor that becomes quite conductive when the plates come close to each
other. The equivalent circuit of the leaky memcapacitor involves a
memcapacitive and memristive system connected in parallel. In the leaky
memcapacitor, the resistance and capacitance depend on the same internal state
variable, which is the displacement of the movable plate. We have performed a
comprehensive analysis showing that several spiking types observed in
biological neurons can be implemented with the leaky memcapacitor. Significant
attention is paid to the dynamic properties of the model. As in leaky
memcapacitors the capacitive and leaking resistive functionalities are
implemented naturally within the same device structure, their use will simplify
the creation of spiking neural networks.
