The Efect of the Earthed Electrode Size on the Ignition Voltage of Low-Pressure RF Capacitive Discharge in Argon

The effect of the grounded electrode diameter on the ignition voltage using 13.56 MHz in argon gas is studied experimentMly. The results indicate a systematic decrease of the breakdown voltage with increasing electrode area for the same pd value. No multi-valued breakdown voltages are observed. The Paschen minimum is not affected by the electrode diameter as long as the parallel plane approximation is valid. A modified Paschen equation which takes into account indirect discharge via the chamber walls at high pd values gives reasonable fits to the experimental data.

Continuous Separation of Multiple Size Microparticles using Alternating Current Dielectrophoresis in Microfluidic Device with Acupuncture Needle Electrodes

The need to continuously separate multiple microparticles is required for the recent development of lab-on-chip technology. Dielectrophoresis（DEP）-based separation device is extensively used in kinds of microfluidic applications. However, such conventional DEP-based device is relatively complicated and difficult for fabrication. A concise microfluidic device is presented for effective continuous separation of multiple size particle mixtures. A pair of acupuncture needle electrodes are creatively employed and embedded in a PDMS（poly-dimethylsiloxane） hurdle for generating non-uniform electric field thereby achieving a continuous DEP separation. The separation mechanism is that the incoming particle samples with different sizes experience different negative DEP（n DEP） forces and then they can be transported into different downstream outlets. The DEP characterizations of particles are calculated, and their trajectories are numerically predicted by considering the combined action of the incoming laminar flow and the n DEP force field for guiding the separation experiments. The device performance is verified by successfully separating a three-sized particle mixture, including polystyrene microspheres with diameters of 3 μm, 10 μm and 25 μm. The separation purity is below 70% when the flow rate ratio is less than 3.5 or more than 5.1, while the separation purity can be up to more than 90% when the flow rate ratio is between 3.5 and 5.1 and meanwhile ensure the voltage output falls in between 120 V and 150 V. Such simple DEP-based separation device has extensive applications in future microfluidic systems.

Sensitization of Microporous Nanocrystalline TiO_2 Electrode with Quantum Sized RuS2 Particles

The microporous nanocry'sta1line TiO2 electrode with large surface roughness factor hasbeen prepared on a conducting glass support. Modification of the TiO2 electrode by in situ preparingquantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorptionspectrum and photocurrent action specmim into visible region. In addition, compared with RuS2 bulknlaterials- a blue shifi in both absorption spectrum and photocurrent action speCtrum of RuS2rriO2elcctrode is obserived and explained in terms of quantum sized effect.

Size and temperature effects on dielectric breakdown of ferroelectric films

The paper introduces a model of dielectric breakdown strength.The model integrated thermal breakdown and defect models,representing the relationship between the electric field of ferroelectric films and dimensional parameters and operating temperature.This model is verified with experimental results of the lead lanthanum zirconate titanate(PLZT)films of various film thickness(J=0.8-3μm),electrode area(A=0.0020-25 mm^(2))tested under a range of operating temperature(T=300-400 K)with satisfying fitting results.Also learned is a relationship that the recoverable electric energy density is directly proportional to the square of breakdown electric field.This relationship is found viable in predicting the electric energy density in terms of variables of d,A,and T for the PLZT films.