Abstract
Phononic crystals can control the propagation of elastic waves by their unique dispersion properties such as band gaps. In recent years, the application of phononic crystals for controlling high-frequency elastic waves, which is important for managing thermal conductivity in the nanoscale and for wireless communication, has been attracting attention. This research proposes a design method of phononic crystals which exhibit band gaps at high band order for the applications with high-frequency elastic waves. To consider manufacturability in nanoscale, phononic crystals made of a single material are assumed. A level set-based topology optimization is used for the design of phononic crystals. An objective function is proposed to achieve a band gap within an aimed range of frequency. As a numerical example, 2-dimensional silicon phononic crystal with hexagonal lattice is optimized. Our approach successfully generates a phononic crystal with a band gap at high band order.
