Pneumatic MEMS switch and method of fabricating the same

A pneumatic micro electro mechanical system switch comprising:

• a substrate;
• a pneumatic actuating unit disposed on the substrate, comprising a plurality of variable air cavities communicating such that when at least one of the plurality of variable air cavities is compressed, the rest are expanded;
• a signal line having a plurality of switching lines, each of which passes through a corresponding one of the plurality of variable air cavities and has a first and a second switching ends disposed in a spaced-apart relation with each other in the corresponding one of the plurality of variable air cavities;
• a switching unit movable with the pneumatic actuating unit to connect the first and the second switching ends of each of the plurality of switching lines when each of the plurality of variable air cavities is compressed;
• and
• a driving unit to drive the pneumatic actuating unit so as to selectively compress at least one of the plurality of variable air cavities,
• wherein at least one of the plurality of variable air cavities is always maintained as compressed, and
• wherein the plurality of switching lines is disposed on and along bottom walls of a plurality of trenches formed in the substrate.