Characterization of MEMS Pressure Sensor Using Acoustics

Direct pressure measurements are integral to aerodynamic investigations, ranging from wind tunnels to flight testing. They are also used in tandem with advanced optical-based methods. While pneumatic pressure scanners and miniature pressure transducers have traditionally dominated the aerospace industry, our team investigated micro-electro-mechanical systems (MEMS) pressure sensors' performance characteristics through rigorous tests to set a new standard for sub-scale to full-scale (Un)manned Aerial Systems. The paper shows a systematic approach to capturing the frequency response, amplitude distortions, and amplitude delays for such sensors. MEMS devices have a characteristic length of less than 1 mm but more than 1 μm. MEMS devices combine electrical and mechanical components and can be either individual units or parts of a more complex mechanical system with integrated electronics. MEMS sensors started as small, relatively simple strain gauge resistive bars made from single-crystal silicon but have since expanded as technology advanced. While MEMS devices are not a new invention, there still exists speculations regarding the increasing performance of MEMS devices compared to legacy devices. The following study will use microphone-based acoustic measurements as a reference dataset to characterize the performance of MEMS pressure sensors performance characteristics. Research outcomes will reveal sensor characteristics such as response time, phase lag, and amplitude distortion. The analysis will validate both the accuracy of reading and the ability to measure unsteady pressure using the unmodified pressure sensor. However, many of these performance characteristics change if the sensor is modified, such as by adding pneumatics to access tight crevices in your model. System identification and acoustics will be used to help characterize the performance of the pressure sensor, given various modifications, such as varying pneumatic tube lengths both on the sensing port and the reference pressure port. A characterization of the sensors settling time, rise time, amplitude distortion, and natural frequency will be provided for external modification an individual may want to make in the context of wind tunnel testing.