Extending of band gaps in silicon based one-dimensional phononic crystal strips

A kind of methodology for the design of silicon based one dimensional phononic crystal strips is demonstrated. It is shown that full bandgaps can be obtained by etching periodic array of semi-circular void holes at the side faces of the strip. The relationships between the phononic bandgaps and parameters are discussed by analyzing band structures and eigenmodes of the phononic crystal strips. We found that with proper design, it is possible to gain a gap-to-midgap ratio up to 62%. The result also shows that higher order eigenmodes are more sensitive to the specified parameters of phononic crystal strips.