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This paper presents a monolithic pulsed high-voltage (HV) generator utilizing a single piezoelectric element (PZT51 disk, 5 mm in diameter and 740 \mum thick) with electrodes series-connected via a flexible polyimide cable. The design, fabrication, assembly, and testing of the HV generator are described. In response to transient mechanical load, the HV generator is evaluated within the stress range from 1 to 5 MPa, and the corresponding peak output voltages vary from 100 to 900 V. Performance comparison between single-electrode pair HV generator and three-electrode pair device indicates series-connected electrodes on a monolithic PZT element greatly boost the output voltage under the same mechanical load conditions. In further tests, the generated high-voltage pulses exceed 1.35 kV and are successfully used to initiate microdischarges on monolithically patterned electrodes across a 75 \mum air gap. The measured capacitance of the test HV generator is 25 pF and the calculated charge delivered to the terminal electrodes in each discharge is 34 nC. The nonlinear piezoelectric property of the PZT51 in transient mode is studied. We experimentally obtain a linear increase of the effective piezoelectric coefficient as the applied pressure increases within the range from 1 to 5 MPa. [2012-0356] [ABSTRACT FROM PUBLISHER]

This paper reports a microfluidic device that integrates electrical and optical features required for field-portable water-chemistry testing by discharge spectroscopy. The device utilizes a dc-powered spark between a metal anode and a liquid cathode as the spectral source. Impurities are sputtered from the water sample into the microdischarge and characteristic atomic transitions due to them are detected optically. A blazed grating is used as the dispersion element. The device is fabricated from stacked glass layers, and is assembled and used with a charge-coupled device (CCD) sensing element to distinguish atomic spectra. Two structural variations and optical arrangements are reported. Detection of Cr and other chemicals in water samples has been successfully demonstrated with both devices. The angular resolution in terms of angular change per unit variation in wavelength (∂θ/∂λ) is experimentally determined to be approximately 0.10 rad/µm, as opposed to the idealized theoretical estimate of 0.22 rad/µm. This is because the microdischarge is uncollimated and not a point source. However, this is sufficient angular resolution to allow critical spectra of metal impurities to be distinguished. [ABSTRACT FROM AUTHOR]

This letter presents a simple and economical paper-based device that is able to generate an array of stable Ar microdischarges. This is a dielectric-barrier-discharge device that exhibits filamentary-type features. The device is sustained by an ac voltage with a 550-V amplitude and 10-kHz frequency. Optical emission spectra show that Ar lines dominate the emission, with a trace amount of CH and \C2 emissions. Despite slight damage, the electrode lifetime exceeds 20 min. Results demonstrate that this device is flexible and is able to achieve maskless patterning of hydrophilic patterns on flat and curved glass surfaces.\hfill[2012-0361] [ABSTRACT FROM PUBLISHER]