Low-mass, high-Q, silicon nitride nanostrings are at the cutting edge of nanomechanical devices for sensing applications. Here we show that the addition of a chemically functionalizable gold overlayer does not adversely affect the Q of the fundamental out-of-plane mode. Instead the device retains its mechanical responsiveness while gaining sensitivity to molecular bonding. Furthermore, differences in thermal expansion within the bilayer give rise to internal stresses that can be electrically controlled. In particular, an alternating current (AC) excites resonant motion of the nanostring. This AC thermoelastic actuation is simple, robust, and provides an integrated approach to sensor actuation.

@article{
  author = {T. S. Biswas and A. Suhel and B. D. Hauer and A. Palomino and K. S. D. Beach and J. P. Davis},
  title = {High-Q gold and silicon nitride bilayer nanostrings},
  publisher = {AIP},
  journal = {Applied Physics Letters},
  volume = {101},
  number = {9},
  eid = {093105},
  numpages = {5},
  pages = {093105},
  year = {2012},
  keywords = {gold; internal stresses; micromechanical resonators; nanostructured materials; silicon compounds; thermal expansion; thermoelasticity},
  doi = {10.1063/1.4748977}
  url = {https://doi.org/10.1063/1.4748977}
}