March 10, 2017 (JST)

Nihon Dempa Kogyo Co., Ltd.
National Research and Development Agency
Japan Aerospace Exploration Agency (JAXA)

Nihon Dempa Kogyo Co., Ltd. and JAXA have codeveloped the world's first sensing system Twin QCM, which under vacuum monitors outgases emitted from components/materials for spacecraft. Twin QCM adopts a new system, which confers Twin QCM improved accuracy and stability compared with conventional QCM systems. Expectations for Twin QCM are high- the system will contribute to contamination countermeasures for production of space apparatus, both for domestic and international use.

In Space, contamination caused by outgassing from plastics, adhesives, and other materials used for manufacturing poses a problem. Contamination on the surfaces of the telephoto lenses which earth and astronomical observation satellites are equipped with can deteriorate the optical performance and quality. It can also result in the reduction of the lifespan of the observation instruments. Selection of appropriate materials based on accurate monitoring is essential to minimize the emission of outgases.

To gauge outgases QTGA method*1 operated by the quartz oscillator sensor has been predominantly employed. Devices are typically comprised of a thin piezoelectric AT-cut quartz crystal sandwiched between two metal excitation electrodes. Conventional QTGA estimates the amount of outgas deposition by calculating the discrepancy of the readings of the two. In the process, analysis of deposition and desorption of the outgas emitted from the sample in the temperature controlled chamber identifies the contents of the outgas. However, the disparities of the behavior and the temperature of the two quartz oscillator sensors undermine high precision.

To overcome the challenge, Nihon Dempa Kogyo Co., Ltd. and JAXA worked on and have succeeded in creating the new QCM sensor, which uses the twin sensor technology. Twin QCM sensor applies the twin sensor method, with both reference and sensing electrodes on one crystal oscillator sensor, which solves the issue of data gaps. Twin sensing technology earns Nihon Dempa Kogyo Co., Ltd. a patent, which operates its NAPiCOS, a bioanalytical device. JAXA, in cooperation with Nihon Dempa Kogyo Co., Ltd., overcame the technical challenge and conducted test evaluation on Twin QCM. Nihon Dempa Kogyo Co., Ltd. is planning on sales of Twin QCM for domestic and foreign space institutions and related industries as its target markets. The product will be identified as JAXA COSMODE*2, and will serve other general businesses, including semiconductor and construction material makers. To them, precise gauging of outgases is of primary concern, as their manufacturing process demands monitoring nanoparticle purity.