MechE PhD Prospectus Defense: Zhiwei Yang

TITLE: METAMATERIAL TOWARDS TERAHERTZ AND ACOUSTIC APPLICATIONS

ABSTRACT: Metamaterials (MMs), defined as artificially constructed materials, have revolutionized research due to their efficiently manipulation of waves at subwavelength scales, enable applications such as perfect absorption, negative refractive index, and cloaking across microwave to visible region. Wavefront manipulation and near field enhancement are two particularly intriguing phenomenon in this domain. In this work, we investigate the fundamental physics and engineering applications of near field enhancement and wavefront manipulation in terahertz and acoustic regimes. First, we explored a vanadium dioxide integrated metamaterial to achieve tunable bound state in the continuum (BIC) for controllable near field enhancement, explained using Coupled mode theory (CMT). Additionally, we designed a phased array-based ultra-open broadband acoustic metamaterial silencer, validated through theoretical, numerical, and experimental methods. This thesis demonstrates the potential of metamaterials for creating advanced functional devices across electromagnetic and acoustic fields, addressing key challenges in real-time tunability, broadband spectrum manipulation, and phase and amplitude control. This thesis paves the way for future innovations in metamaterial-based technologies for sensing and noise reduction.

COMMITTEE: ADVISOR/CHAIR Professor Xin Zhang, ME/ECE/BME/MSE; Professor Richard Averitt, UCSD Physics; Professor Chuanhua Duan, ME/MSE; Professor Thomas Bifano, ME/MSE/BME/ECE