Development of Wide-Band Vibration Sensors Based on Existing Process Platforms
Measurement and spectral analysis of mechanical vibrations is required in different domestic, geophysical and industrial applications such as intrusion detection and identification of mechanical faults in machines. Currently, no low cost, low power, and compact vibration sensor solution exists that can provide frequency distribution data for the measured vibrations.
This work presents implementation and characterization of building blocks of a low-power miniaturized vibration spectrum analyzer. To cover the entire targeted frequency range (0-10kHz), two different device configurations, both utilizing piezoresistive strain gauges on microscale cantilevers, have been fabricated using a standard CMOS process with minimal mask-less post-CMOS micro-machining. The lower frequency configuration utilizes the entire CMOS chip as a cantilever with on-chip piezoresistive strain gauges. A high-density mass is attached to the free end of the chips to lower the flexural resonance frequency (<500Hz) and achieve sub-mg resolution. The higher frequency configuration utilizes arrays of integrated cantilevers within individual CMOS chips. Each cantilever detects and measures amplitude of vibrations at the vicinity of its resonance frequency (where the vibration amplitude is amplified by the cantilever Q-factor). Sensitivities as high as 9.73mV/g (at DC for 1mW of power consumed) and 14.5mV/g (at 7.2kHz for 1mW of power consumed) have been obtained for the lower and higher frequency configurations with a minimum resolution of 1.02mg (for 1mW power consumption) and 0.2mg (for 1mW power consumption) respectively.
|Texas Analog Center of Excellence and Analog/Mixed-Signal Circuits, Systems and Devices Review|
Tuesday, Oct. 17, 2017, 8 a.m. — Thursday, Oct. 19, 2017, noon CT
Richardson, TX, United States