Micromachined Silicon Acoustic Delay Lines for High-Frequency Ultrasound Sensing and Imaging

This paper reports a new micromachined silicon acoustic delay line (SADL) design for transmitting high-frequency ultrasound signals while adding a certain amount of true time delay. Compared to traditional structures, with the use of a novel thin-film backside linker, the new SADL design can significantly increase the mechanical stiffness of the SADL structure for easy handling and assembly without degrading its acoustic performance. It can be easily scaled up or down to provide different ultrasound frequency response and time delays. For demonstration, high-frequency ultrasound transmission through a multi-channel SADL array has been successfully achieved. The new SADL design could provide a new practical approach for the development of high-frequency ultrasound arrays for high-resolution and high-speed ultrasound sensing & imaging applications.