A Tunable Strain Sensor Using Nanogranular Metals

• Main Authors: Friedemann Völklein, Alexander Kaya, Jens Müller, Pintu Das, Heiko Reith, Fabrizio Porrati, Roland Sachser, Markus Baranowski, Christina Grimm, Christian H. Schwalb, Michael Huth
• Format: Article
• Language: English
• Published: MDPI AG 2010-11-01
• Series: Sensors
• Subjects: cantilevers; electron beam induced deposition; granular metals; strain sensors
• Online Access: http://www.mdpi.com/1424-8220/10/11/9847/
• ISSN: 1424-8220

This paper introduces a new methodology for the fabrication of strain-sensor elements for MEMS and NEMS applications based on the tunneling effect in nano-granular metals. The strain-sensor elements are prepared by the maskless lithography technique of focused electron-beam-induced deposition (FEBID) employing the precursor trimethylmethylcyclopentadienyl platinum [MeCpPt(Me)3]. We use a cantilever-based deflection technique to determine the sensitivity (gauge factor) of the sensor element. We find that its sensitivity depends on the electrical conductivity and can be continuously tuned, either by the thickness of the deposit or by electron-beam irradiation leading to a distinct maximum in the sensitivity. This maximum finds a theoretical rationale in recent advances in the understanding of electronic charge transport in nano-granular metals.