Authors: T. Salthammer, S. Merzsch, E. Peiner, I. Kirsch, E. Uhde, A. Waag, H.S. Wasisto
Affilation: Fraunhofer WKI, Germany
Pages: 123 - 126
Keywords: MEMS, personal sampler, workplace
The increasing industrial use of manufactured nano-particles demands for work place monitors and personal samplers to assess the exposure of production workers. Such particles are typically measured using comparatively complex and costly instrumentation. These instruments are often too large for personal mobile operation. Recently, thermally excited MEMS cantilevers were proposed to determine the particle mass from the resonance frequency shift measured after exposure. In this joint research project cantilevers of slender geometry providing a large surface-to-volume ratio, driven by low-power piezoelectric AlN thin film actuators, were used and a mass resolution of 5 ng was observed. The device presented in this paper is a small, lightweight personal sampler utilizing a resonating MEMS-cantilever as sensing element. Important considerations for the development were: Low production costs (< 100 Euro), battery lifetime of at least 8h (one shift), sampler weight < 500 g, sufficient stability against climate changes, rugged design. The personal sampler is validated in environmental test chambers against test aerosols generated from technical nano-particles (SiO2, carbon, TiO2, Ag, PTFE).