MEMS-Based Sensor for Monitoring Cabin Air Quality on the ISS

In this Phase I project Aerodyne Microsystems Inc. (AMI) will investigate the feasibility of a miniaturized, low power, and inexpensive sensor to provide real-time measurements of particulate matter (PM). The MEMS-based instrument would be suitable for monitoring indoor aerosols in spacecraft cabins such as the ISS and would offer significant improvements over legacy solutions including reduced form factor and lower power consumption. The system utilizes a hybrid detection technique to monitor aerosol sizes from 50 um to 10 nm. For PM smaller than 2.5 um, the systems employs the thermophoretic deposition of particulates from a sample stream onto a thin-film bulk acoustic wave resonator (FBAR), and determines the mass deposited by measuring the frequency shift of an electronic oscillator. PM larger than 2.5 um (including lint and fibers) is optically measured with a novel detector configuration. The proposed technique is suitable for both spherical and non-spherical aerosols. The Phase I project will design, prototype and test key modules of the instrument, simulate and analytically model device behavior, develop interface and control electronics, and develop novel techniques for aerosol sampling and handling. AMI's proposed monitor is portable, offers an intuitive user interface, requires minimal maintenance, and can maintain calibration for extended periods of time. The platform requires no volatile working fluid, operates in low gravity, and offers the ability to log data for longer-term indoor air quality surveys.