Back in the old days, the really good radios used mechanical
filters. Now, according to this item, we could see a whole new
type of mechanical filter, this time built with a
microelectromechanical (MEMS) device. Tiny ‘MEMS’ Devices to
Filter, Amplify Electronic Signals Purdue University News
(08/10/09) Venere, Emil Purdue University researchers are
developing a new class of microelectromechanical (MEMS) devices
called resonators that contain vibrating, hair-thin structures
and could be used to filter electronic signals. Resonators
vibrate in specific patterns, so they can cancel out signals
that contain certain frequencies while allowing others to pass,
making these devices useful for applications such as refining
cell phone signals. The devices have led to a new type of band-
pass filter, which is used in electronics to allow some signals
to pass while blocking others, says Purdue professor Jeffrey
Rhoads. This new class of resonators represents a potential way
to further the miniaturization of band-pass filt