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Atmospheric-pressure, non-equilibrium plasmas are susceptible to instabilities and, in particular, to arcing (glow-to-arc transition). Spatially confining the plasma to dimensions of 1 mm or less is a promising approach to the generation and maintenance of stable, glow discharges at atmospheric-pressure. Often referred to as microdischarges or microplasmas, these weakly-ionized discharges represent a new and fascinating realm of plasma science, where issues such as the possible breakdown of ‘pd scaling’ and the role of boundary-dominated phenomena come to the fore. Microplasmas are generated under conditions that promote the efficient production of transient molecular species such as the rare gas excimers, which generally are formed by three-body collisions. Pulsed excitation on a sub-microsecond time scale results in microplasmas with significant shifts in both the temperatures and energy distribution functions associated with the ions and electrons. This allows for the selective production of chemically reactive species and opens the door to a wide range of new applications of microplasmas. The implementation of semiconductor and microelectronics and MEMs microfabrication techniques has resulted in the realization of microplasma arrays as large as 250,000 devices. Fabricated in silicon or ceramics with characteristic device dimensions as small as 10 µm and at packing densities up to 104 cm−2, these arrays offer optical and electrical characteristics well suited for applications in medical diagnostics, displays and environmental sensing. Several microplasma device structures, including their fundamental properties and selected applications, will be discussed.

DavideMariotti is a Professor of Plasma Science and Nanoscale Engineering with Ulster University in UK. He has previously worked internationally in Japan and USA and both in academic and industry. His research encompasses the design and development of innovative plasma-based processes to explore new materials opportunities. Concurrently to a strong application focus in photovoltaics and more broadly in energy applications, his research is also strongly driven by scientific discovery. Kostya (Ken) Ostrikov is aProfessor with Queensland University of Technology, Australia, a Founding Leader of the CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, and Academician of the Academy of Europe and the European Academy of Sciences. His research focuses on nanoscale control of energy and matter contributes to the solution of the grand challenge of directing energy and matter at nanoscales, to develop renewable energy and energy-efficient technologies for a sustainable future.is made on synergistic, complementary features of the plasmas that make them a versatile tool in materials-related applications.We therefore examine the recent progress in microplasmabased synthesis of advanced nanomaterials, highlight the key features of microplasmas, and discuss salient examples of Adv.

Cylindrical microdischarge cavities 200–400 μm in diameter and 0.5–5 mm in depth have been fabricated in silicon and operated at room temperature with neon or nitrogen at specific power loadings beyond 10 kW/cm3. The discharges are azimuthally uniform and stable operation at N2 and Ne pressures exceeding 1 atm and ∼600 Torr, respectively, has been realized for 400 μm diameter devices. Spectroscopic measurements on neon discharges demonstrate that the device behaves as a hollow cathode discharge for pressures >50 Torr. As evidenced by emission from Ne and Ne+ (2P,2F) states as well as N2 (C→B) fluorescence (316–492 nm), these discharge devices are intense sources of ultraviolet and visible radiation and are suitable for fabrication as arrays.

A label free biosensor based upon a vertically emitting distributed feedback ͑DFB͒ laser has been demonstrated. The DFB laser comprises a replica-molded, one-dimensional dielectric grating coated with laser dye-doped polymer as the gain medium. Adsorption of biomolecules onto the laser surface alters the DFB laser emission wavelength, thereby permitting the kinetic adsorption of a protein polymer monolayer or the specific binding of small molecules to be quantified. A bulk sensitivity of 16.6 nm per refractive index unit and the detection of a monolayer of the protein polymer poly͑Lys, Phe͒ have been observed with this biosensor. The sensor represents a departure from conventional passive resonant optical sensors from the standpoint that the device actively generates its own narrowband high intensity output without stringent requirements on the coupling alignments, resulting in a simple, robust illumination and detection configuration.