Directional audio systems typically use parametric array loudspeakers (PALs), which rely on nonlinear ultrasound beam interactions for localized sound delivery. However, conventional PALs require phased arrays composed of many ultrasonic emitters, limiting their practicality due to high costs and system complexity. In this presentation, we introduce a compact alternative: the metasurface-integrated parametric array loudspeaker (MiPAL). MiPAL combines a single piezoelectric transducer with a co-designed acoustic metasurface, creating a simple but effective platform for directional sound generation. Using a unified design approach—metasurface-transducer co-design and complex acoustic field analysis—we achieve broadband directional audio spanning around 500 Hz to 10 kHz. This work offers a foundation for next-generation sound technologies.
Oh et al. (Wed,) studied this question.