Ion irradiation of microelectromechanical resonators

1 . A method of enhancing an electromechanical coupling coefficient of a microelectromechanical (“MEMS”) device, the method comprising:

applying heavy particle ion radiation to the MEMS device at a fluence of at least 1×10 14 cm −2 which can cause an increase in k 2 e ff of at least 5%.

2 . The method of claim 1 , wherein the fluence is less than 5×10 14 cm −2 .

3 . The method of claim 1 , wherein the heavy particle ion radiation includes silicon ions, argon ions, helium ions, carbon ions, and neon ions.

4 . The method of claim 3 , wherein an energy of the silicon ions is 2 MeV.

5 . The method of claim 1 , wherein the MEMS device includes a substrate, a transduction layer on the substrate, a conductive layer on the transduction layer, and, optionally, a semiconductor layer between the substrate and the transduction layer.

6 . The method of claim 5 , wherein at least 50% of dislocations created by the applied heavy particle ion radiation are located in the transduction layer of the MEMS device.

7 . The method of claim 6 , wherein the dislocations are electron-hole pairs.

8 . A bandpass filter comprising:

a plurality of MEMS devices fabricated in accordance with the method of claim 1 , wherein the MEMS of the plurality are electronically or mechanically coupled.

9 . The bandpass filter of claim 8 , wherein the plurality of MEMS devices includes a first MEMS device in series with a second MEMS device.

10 . The bandpass filter of claim 9 , further comprising:

a third MEMS device operably coupled to the first and second MEMS devices as a shunt resonator.

11 . The bandpass filter of claim 10 , further comprising:

a substrate bias electrode.