A micro bio-inspired teeter-totter velocity sensitive microphone structure

This study experimentally examines the development of a bio-inspired teeter-totter low-noise velocity-sensitive microphone. Several microscale prototypes were constructed using a micromanipulator, microscope, epoxy, super glue, and basic materials. None of the prototypes presented in this article represent a fully optimized, functional device; however, they could demonstrate how the performance of this flow-sensing microphone can be improved. The simplest design features a beam held by a hinge inside a cavity. By modifying this structure, such as altering the hinge material and increasing the beam's surface area (e.g., by adding more beams), the thermal noise floor, acoustic response, phase response, and pressure-referred noise of different samples are measured and compared. The results demonstrate that softening the hinge (by making it thin and flexible), lowering the beam rocking mode frequency, increasing the surface area while maintaining a reasonable structure weight, and keeping the first bending mode of the beam at a higher frequency out of the range of normal hearing significantly improves the sensor's performance. These findings offer valuable insights into designing high-performance, low-noise acoustic particle velocity sensors.