Other

Center for Advanced Meta-materials

Jae Hwa Lee

Hak Joo Lee

Jong Jin Park

Eun Bok

Disclosed herein is an acoustic metamaterial structure which can effectively reduce noise in a specific frequency range through formation of an acoustic bandgap, wherein the specific frequency range is determined by a periodic structure formed by an array of multiple unit cells. The acoustic metamaterial structure includes multiple first unit cells each including a first space having a first cross-sectional area and a second space disposed downstream of the first space in a flow direction of fluid to communicate with the first space, the second space having a second cross-sectional area larger than the first cross-sectional area, wherein the acoustic metamaterial structure reduces noise in a specific frequency range through formation of an acoustic bandgap, the specific frequency range being determined by a periodic structure formed by an array of the first space and the second space.

Acoustic metamaterial structure

The surgical saw according to the present invention comprises an arm fixed by mounting the rear end portion thereof in a jaw of a handle; and a double saw blade part connected with the front end portion of the arm and having two saw blades arranged side by side in a certain distance. In case that the surgical saw is used in surgeries for cutting off cheek bones, the surgical saw can precisely cut off portions of the cheek bones in a width set in advance by precisely cutting off two positions of the cheek bones in a precise cutting-off length at the same time so that the portions of cheek bones can be conveniently cut off, the periods of time for surgeries can be reduced, and an occurrence frequency of surgery aftereffects due to different cutting-off widths for the left and right cheek bones can be reduced.

Growing community of inventors

Daejeon, South Korea

Jae Hwa Lee