Description: This SBIR project seeks to develop a miniature sensor for mass measurement of size-classified aerosols. A cascade impactor will be used to classify aerosol sample into 8 uniform bins on a logarithmic scale, covering an aerodynamic size range of 0.01 to 10 microns. In each of the 8 stages aerosols will be deposited on a MEMS microbalance that will record aerosol mass in real-time. The proposed device incorporates state-of-the-art MEMS microbalances from the subcontractor femtoScale in the applicant MSP Corporation's advanced cascade impaction technology. With the help of a consultant, who has decades of experience in airborne aerosol measurements, we propose to adapt this device to unpiloted aircrafts, like Black Hawk for NASA's Airborne Science Program. During Phase I, we propose to design a miniature cascade impactor with a low flow rate of 0.5 liters per minute or smaller. A prototype will be built with 8 stages pertaining to 8 aerosol size classes. MEMS microbalance on each stage will measure the deposited aerosol mass with a frequency of 1 Hz. This prototype will be tested and validated in Phase I and the final flight-worthy deliverable will be built in Phase II. The proposed device is expected to weigh less than 5 kg and consume about 100 W electrical power. Besides being valuable for NASA's airborne science program, this instrument will have numerous R&D and industrial monitoring applications that need real-time aerosol measurements down to 0.01 micron.

Benefits: Our proposed instrument has applications in NASA's Airborne Science Program. It will be suitable for all the aircrafts used in this program, especially, unpiloted aircrafts like Global Hawk. According to NASA Webpage https://airbornescience.nasa.gov/instrument/aircraft/Global Hawk, multiple instruments are being used for atmospheric research on this unpiloted aircraft including aerosol spectrometers based on optical signals and condensation nuclei counting. Our proposed instrument will complement the existing suite of instruments with its unique capability of classifying particles by aerodynamic size and providing a true mass distribution. Further, it will save the size-classified aerosol samples for further analysis after the end of the flight mission.

Atmospheric research programs of non-NASA government agencies would also benefit from the proposed product. Some of these programs are (i) Atmospheric System Research Program, DOE, (ii) National Center for Atmospheric Research, sponsored by NSF, (iii) Earth System Research Laboratory, NOAA, DOC. Similar programs exit worldwide. The proposed product will also be valuable for R&D work on aerosols in (i) indoor environments, (ii) occupational health and safety settings, (iii) powder processing, (iv) medical inhalers, (v) automotive exhaust, etc. Potential customers are academic, non-academic and industrial research laboratories. Our instrument would also be used in industrial manufacturing environment for routine monitoring of aerosol distribution and concentration in such applications as medical inhaler manufacturing. In some industrial applications, such as powder production (e.g. in pharmaceutical or food industry), it would be possible to use the output of our sensor to control the manufacturing processes automatically. Semiconductor structures and nanotechnology devices that are manufactured and assembled in clean rooms are becoming smaller and smaller. There is an emerging need for a contaminant particle measuring instrument for these applications, capable of measuring particles down to 10 nm in real-time. Our proposed instrument is well-poised for this application.