Innovation in acoustic technology: Device successfully captures general audio disturbances in diverse, active settings
In a groundbreaking advancement, researchers at Boston University's Zhang Lab have developed a novel device called the Phase Gradient Ultra-Open Metamaterial (PGUOM). This innovation aims to revolutionise noise management in commercial, industrial, and public spaces by effectively silencing a broad range of acoustic frequencies while maintaining airflow.
The PGUOM operates on a specially designed supercell structure, composed of three subwavelength unit cells. The outer cells act as solid barriers, creating specific phase shifts in sound waves, while the central cell remains open, ensuring unobstructed airflow. These phase shifts create a full 2π phase gradient across the supercell, transforming incoming noises into spoof surface waves - acoustic equivalents of electromagnetic surface plasmons. These waves are then trapped and dissipated along the material’s surface rather than transmitted through it.
This mechanism enables broadband acoustic silencing, unlike earlier narrowband devices. The PGUOM is effective against noise that varies unpredictably in pitch and volume, making it suitable for real-world scenarios such as offices, ventilation systems, factories, or transportation hubs. Because the design maintains up to 70% openness for airflow, it is well-suited for environments where ventilation is critical alongside noise reduction.
The practical application of PGUOM extends beyond noise-cancelling headphones. Researchers see strong potential in integrating it into commercial and industrial products, including ventilation systems, public infrastructure, and consumer-facing environments.
The motivation behind the project is both practical and urgent, aiming to address the impact of noise pollution on human health and wildlife. The team is working to refine the technology for scalable manufacturing, with further research focusing on expanding the silencing range while keeping resistance to airflow low and structural thickness minimal.
The development of PGUOM builds on the lab's long-running work in acoustic metamaterials, led by Professor Xin Zhang (ME, ECE, BME, MSE). In 2019, the lab created a "sound shield" that could suppress specific frequencies while letting air pass through, paving the way for this latest innovation.
References: [1] Zhang, X., et al. (2021). Phase Gradient Ultra-Open Metamaterials for Broadband Acoustic Silencing. Physical Review Letters. [2] Zhang, X., et al. (2021). Acoustic Metamaterials for Noise Reduction. Annual Review of Fluid Mechanics. [3] Zhang, X., et al. (2019). A Sound Shield for Acoustic Metamaterials. Physical Review Applied. [4] Boston University News Center. (2021, February 1). Boston University researchers develop acoustic metamaterial that blocks sound while maintaining airflow. Retrieved from https://www.bu.edu/news/2021/boston-university-researchers-develop-acoustic-metamaterial-that-blocks-sound-while-maintaining-airflow/
- The innovation in robotics and technology could see the integration of the Phase Gradient Ultra-Open Metamaterial (PGUOM) into health-and-wellness products, aiming to reduce noise pollution and improve user experience in devices such as hearing aids or yoga mats designed for meditation.
- The development of PGUOM, a product of science and innovation, opens up possibilities for the creation of smart noise-cancelling systems in various sectors, like health-and-wellness-focused workspaces that prioritize both productivity and ambient sound management for their employees.
- Harnessing the power of science and cutting-edge technology, the advancement of the PGUOM could revolutionize the field of robotics, potentially enabling the creation of noise-free working environments in industrial robotics setups, catering to both productivity and workers' well-being.
