Exploring microdischarges for portable sensing applications

Abstract

This paper describes the use of microdischarges as transducing elements in sensors and detectors. Chemical and physical sensing of gases, chemical sensing of liquids, and radiation detection are described. These applications are explored from the perspective of their use in portable microsystems, with emphasis on compactness, power consumption, the ability to operate at or near atmospheric pressure (to reduce pumping challenges), and the ability to operate in an air ambient (to reduce the need for reservoirs of carrier gases). Manufacturing methods and performance results are described for selected examples.

Preliminary Figures of Merit for Isotope Ratio Measurements: The Liquid Sampling-Atmospheric Pressure Glow Discharge Microplasma Ionization Source Coupled to an Orbitrap Mass Analyzer

“…One area that has not seen equivalent size reductions is the field of atomic spectroscopy, which still relies heavily on standard inductively coupled plasma (ICP) sources for optical emission spectroscopy and mass spectrometry. Despite the general activity in the field of microplasmas, including that of the electrolyte cathode discharge (ELCAD) presented by Cserfalvi and improved by Hieftje (explored as a source for optical emission analysis) [7][8][9][10][11][12][13][14][15], there has been no commercially accepted replacement of the ICP for use in the field of elemental analysis and none in the portable arena.…”

Microplasma Ionization of Volatile Organics for Improving Air/Water Monitoring Systems On-Board the International Space Station

“…The device's core consists of two conductive molybdenum foil discs (diameter = 8 mm, thickness = 100 μm) and an insulating mica disc (diameter = 10 mm, thickness = 100 μm) in a metal-insulator-metal (MIM) configuration. The cylindrical micro-discharge cavity between the planar electrodes was fabricated by laser etching a 300 μm diameter hole through the center of the three discs [16]. The discs were aligned and mounted in an aluminum and PEEK screw-capsule housing containing a gas feed line and electrical contacts connected to a PS350/5000 V-25 W high voltage supply (Stanford Research Systems, Inc., Sunnyvale, CA, USA).…”

“…Steady growth in the development of microplasmas and other low power plasma for analytical chemistry applications has been seen in the recent literature [14,15], the driving force being the potential for developing small, low power devices with reduced operational cost and increased fieldability [16,17], with many focused on coupling to portable low resource MS instrumentation [18][19][20]. Microplasma-based miniature ion sources operated under ambient sampling/ionization conditions have the additional advantages of high sample throughput and simplicity, enabling direct analysis with little or no sample preparation [21,22].…”

Rapid Prototyping of Hybrid, Plastic-Quartz 3D-Chips for Battery-Operated Microplasmas

“…For instance, there are several research groups world-wide working on microplasmas for chemical analysis applications. Thus far, microplasmas have been described in books (Becker et al, 2004;Hutchison, 2005;Lieberman, 2005;Fridman, 2008;Hippler at al., 2008;Fridman, 2011;Inan & Gokowski, 2011), in review articles (Karanassios, 2004;Broekaert & Siemens, 2004;Broekaert & Jakubowski, 2007;Gianchandani et al, 2009) and in papers describing their analytical applications (Karanassios et al, 2007;Weagant & Karanassios, 2009;Weagant et al, 2010;Weagant et al, 2011;Vautz et al, 2008;Olenici-Craciunescu, 2009;Hoskinson et al, 2011;Marcus et al, 2011), their characteristics and their other uses (Janasek et al, 2006;Frimat et al, 2009;Olenici-Craciunescu, 2011;Xu & Hopwood, 2007;Zhu et al, 2008;Chen & Eden, 2008;Wright & Chianchandani, 2009;McKay et al, 2010;Liu et al, 2010). From the cited literature it can be concluded that although microplasma research has been (mostly) application driven, "microplasmas represent a new realm in plasma physics that still is not fully understood" (Iza, 2008).…”