The development and analysis of plasma microfluidic devices

Microfluidic devices were studied here to determine the potential for lab-on-a-chip applications based on the dielectric barrier discharge (DBD) mode of activation. This type of discharge is usually formed between two parallel electrodes, with a separation between 0.1 and 1 mm, where one or both electrodes are covered with a dielectric barrier. Different working conditions were considered: A sinusoidal voltage of up to 9 kV peak to peak with frequencies from 10 kHz to 40 kHz has been applied to the electrodes imbedded in PDMS layers. The micro channel width was maintained at 50 and 100 gm, and the pressure was varied between 35 kPa and 103 kPa above atmospheric pressure, using helium, neon and nitrogen gases respectively, for the formation of the microplasma discharges. This generated micro discharge currents in the range of 0.1 to 12 mA at a flow rate of 0.012 I min(-1), and can be seen as current filaments of about 100 ns duration on the time resolved electrical waveform. Current-Voltage (I-V) measurement results obtained show a sharp peak in the discharge current at the breakdown voltage. Results also confirm the dependence of discharge current on frequency, gas composition, microchip geometry and flow rate. (C) 2011 Elsevier B.V. All rights reserved.