SBIR-STTR Award

The quartz crystal microbalance (QCM) has been the accepted instrument to monitor molecular deposition on a spacecraft surface so that the level of surface contamination can be determined. The mass sensitivity of the present QCM, 0.23 Hz cm2/nanogram for a 10 MHz crystal, cannot meet the 1 nanogram/cm2 required by NASA. A new type of piezoelectric crystal, a 200 MHz surface-acoustic-wave (SAW) resonator, piezoelectric crystal, could increase the mass sensitivity two orders of magnitude over the conventional bulk crystals. A 200 MHz, SAW-resonator, mass microbalance has been developed for aerosol measurements and could be used to measure microdepositions. With a sensitivity of 90 Hz cm2/nanogram, such a SAW device can monitor the 1 nanogram/cm2 deposits with a frequency shift of 90 Hz, which is about 400 times that of a 10 MHz bulk crystal (per unit area). By transferring the firm's SAW mass microbalance technology and by using the existing QCM technology, an efficient and cost- effective program is possible to develop a small, lightweight, space-certifiable microdeposition monitor.

Potential Commercial Applications:
A small, lightweight, space- certified, SAW-resonator microdeposition monitor would provide an economical, compact, reliable, and extremely sensitive instrument to measure molecular mass deposition in both vacuum chambers and space simulation chambers, and in applications such as the space station.