  One of the challenges of nanoelectromechanical systems (NEMS) is the
effective transduction of the tiny resonators. Vertical structures, such as
nanomechanical pillar resonators, which are exploited in a wide range of
fields, such as optomechanics, acoustic metamaterials, and nanomechanical
sensing, are particularly challenging to transduce. Existing electromechanical
transduction methods are ill-suited as they complicate the pillars' fabrication
process, put constraints on the pillars' material, and do not enable a
transduction of freestanding pillars. Here, we present an electromechanical
transduction method for single nanomechanical pillar resonators based on
surface acoustic waves (SAWs). We demonstrate the transduction of freestanding
nanomechanical platinum-carbon pillars in the first-order bending and
compression mode. Since the principle of the transduction method is based on
resonant scattering of a SAW by a nanomechanical resonator, our transduction
method is independent of the pillar's material and not limited to pillar-shaped
geometries. It represents a general method to transduce vertical mechanical
resonators with nanoscale lateral dimensions.
