| Recent development in microelectromechanical systems (MEMS) has been essential in the advancement of the fluid mechanics field. The ability to fabricate flow sensors in the micro scale allows researchers to measure fluid parameters at an increasing performance, resolution, and functionality. A wide variety of transducers beyond the fluid mechanics field have also taken the advantage of this emerging technology. However, the existing MEMS technology has some limitations in its application to sensors such as the widely different processing technology required and the need to use bulk substrate etching that removes the available area for circuitry. Such issues limit the application and functionality of the current MEMS flow sensors.; We report the development of a new fabrication platform that can address those potential issues. This technology uses surface micromachining in conjunction with a 3D assembly process to raise the sensors out-of-plane to, which provides thermal isolation and allows the sensors to access the modality such as flow speed. Using this platform, we have created a hot-wire anemometer (HWA) for airflow measurement; micro-pirani gauge for sub atmospheric pressure measurement; and a time-of-flight flow sensor to measure water flow rate.; Based on the same platform, we further developed a novel bio-inspired artificial hair cell (AHC) sensor. This type of sensor is used in the biological world to perform a variety of sensing modality such as touch, airflow, hearing, and acceleration. The first two modalities has been achieved and characterized.; From biological inspiration, an artificial version of the biological lateral line system is then created with an array of our sensors to demonstrate hydrodynamic flow imaging.; In addition, we use the fabrication platform to integrate 8 sensor array with on-chip signal conditioning using a commercial operational amplifier circuit. A new method to make the sensor array flexible is also proposed. |
