APL: Interdisciplinary and General Physics http://scitation.aip.org/ APL: Interdisciplinary and General Physics Autonomous microfluidic transport using electrowetting-based valves and integrated cells http://link.aip.org/link/?APL/95/204105/1&agg=rss Papaorn Siribunbandal, Shigeki Yamaguchi, Kenichi Kojima, Junji Fukuda, and Hiroaki Suzuki<br/> Autonomous control of the transport of solutions in microfabricated flow channels using electrowetting-based valves and integrated electrochemical cells is proposed. An electrowetting-based valve formed with a gold electrode was opened when an electrolyte solution reached a zinc electrode in a contr ... [Appl. Phys. Lett. 95, 204105 (2009)] published Thu Nov 19, 2009. Electrohydrodynamic repulsion of droplets falling on an insulating substrate in an electric field http://link.aip.org/link/?APL/95/204106/1&agg=rss Bumjoo Kim, Intae Kim, Sang W. Joo, and Geunbae Lim<br/> Control technique for charged droplets, named as electrohydrodynamic droplet repulsion (EDR), is reported. Charged droplets emitting from a capillary and falling down toward an insulating substrate are deflected from their intended impact point due to the like polarity of previously fallen droplets. ... [Appl. Phys. Lett. 95, 204106 (2009)] published Thu Nov 19, 2009. Superhydrophobic floatability of a hydrophilic object driven by edge effect http://link.aip.org/link/?APL/95/204107/1&agg=rss Feng-Ming Chang, Yu-Jane Sheng, and Heng-Kwong Tsao<br/> It is generally believed that a water-repellent surface is necessary for small insects to stand on water. Through a combined experimental and theoretical study, we demonstrate that an object with hydrophilic surface can float with apparent contact angle greater than 90 degrees due to edge effect. T ... [Appl. Phys. Lett. 95, 204107 (2009)] published Thu Nov 19, 2009. Sound control by temperature gradients http://link.aip.org/link/?APL/95/204102/1&agg=rss Jose Sanchez-Dehesa, Mitko I. Angelov, Francisco Cervera, and Liang-Wu Cai<br/> This work reports experiments showing that airborne sound propagation can be controlled by temperature gradients. A system of two heated tubes is here used to demonstrate the collimation and focusing of an ultrasonic beam by the refractive index profile created by the temperature gradients existing ... [Appl. Phys. Lett. 95, 204102 (2009)] published Wed Nov 18, 2009. Preparation of monodisperse emulsions by hydrodynamic size fractionation http://link.aip.org/link/?APL/95/204103/1&agg=rss Linas Mazutis and Andrew D. Griffiths<br/> We describe a microfluidic system allowing fast and efficient size-dependent separation of droplets using hydrodynamics. This system allows efficient fractionation of droplets with a difference in volume as small as 2.33-fold (corresponding to a 1.33-fold difference in diameter of spherical droplets ... [Appl. Phys. Lett. 95, 204103 (2009)] published Wed Nov 18, 2009. Fabrication of a transparent and flexible thin film transistor based on single-walled carbon nanotubes using the direct transfer method http://link.aip.org/link/?APL/95/204104/1&agg=rss S. H. Tseng and N. H. Tai<br/> The fabrication of transparent and flexible thin film transistors (TFTs), using single-walled carbon nanotube (SWCNT) networks as bottom gates and conducting channels and polymethylmethacrylate (PMMA) as an insulating layer, by the direct transfer method is demonstrated. The fabricated SWCNT-TFTs ex ... [Appl. Phys. Lett. 95, 204104 (2009)] published Wed Nov 18, 2009. Fractal growth in organic thin films: Experiments and modeling http://link.aip.org/link/?APL/95/204101/1&agg=rss Gengxin Zhang, Brandon Weeks, Richard Gee, and Amitesh Maiti<br/> Optical microscopy and atomic force microscopy were used to investigate the solidification process of the organic energetic material pentaerythritol tetranitrate thermally deposited on a silicon surface. The metastable films spontaneously undergo dendrite formation where the measured fractal dimensi ... [Appl. Phys. Lett. 95, 204101 (2009)] published Mon Nov 16, 2009. Homologous temperature dependence of global surface scaling behaviors of polycrystalline copper films http://link.aip.org/link/?APL/95/194104/1&agg=rss J. J. Yang, B. Liu, Y. Wang, and K. W. Xu<br/> A strategy integrating structure zone model with dynamic scaling theory was proposed to study the global surface dynamics of polycrystalline Cu films deposited at different homologous temperature T/T. The evolution of roughness exponent alpha and growth exponent beta reveals a transition from random ... [Appl. Phys. Lett. 95, 194104 (2009)] published Thu Nov 12, 2009. Particle transport in porous media: The role of inertial effects and path tortuosity in the velocity of the particles http://link.aip.org/link/?APL/95/194103/1&agg=rss Guido Kampel, Guillermo H. Goldsztein, and Juan C. Santamarina<br/> Fluid in porous media flows through tortuous paths. If the size of the solid particles suspended in the fluid and the fluid velocities are large enough, Brownian motion effects may not be dominant. In this parameter regime, the average velocity of the particles is different than that of the fluid. W ... [Appl. Phys. Lett. 95, 194103 (2009)] published Thu Nov 12, 2009. Realization of reliable and flexible logic gates using noisy nonlinear circuits http://link.aip.org/link/?APL/95/194102/1&agg=rss K. Murali, I. Rajamohamed, Sudeshna Sinha, William L. Ditto, and Adi R. Bulsara<br/> It was shown recently [Murali et al., Phys. Rev. Lett. 102, 104101 (2009)] that when one presents two square waves as input to a two-state system, the response of the system can produce a logical output (NOR/OR) with a probability controlled by the interplay between the system noise and the nonlinea ... [Appl. Phys. Lett. 95, 194102 (2009)] published Wed Nov 11, 2009. Effect of anisotropic charge transport on device characteristics of polymer solar cells http://link.aip.org/link/?APL/95/194101/1&agg=rss Manas Shah, Victor Pryamitsyn, and Venkat Ganesan<br/> We present a model for photovoltaic device characteristics based on drift-diffusion ideas which allows for prescription of arbitrary morphologies of donor and acceptor phases while simultaneously incorporating the role of anisotropic charge transport of holes and excitons. We use such a model to add ... [Appl. Phys. Lett. 95, 194101 (2009)] published Wed Nov 11, 2009. Infrared carpet cloak designed with uniform silicon grating structure http://link.aip.org/link/?APL/95/184102/1&agg=rss Xiaofei Xu, Yijun Feng, Yu Hao, Juming Zhao, and Tian Jiang<br/> Through a particularly chosen coordinate transformation, we propose an optical carpet cloak that only requires homogeneous anisotropic dielectric material. The proposed cloak could be easily imitated and realized by alternative layers of isotropic dielectrics. To demonstrate the cloaking performance ... [Appl. Phys. Lett. 95, 184102 (2009)] published Fri Nov 6, 2009. Effect of pressure on electrospray characteristics http://link.aip.org/link/?APL/95/184103/1&agg=rss Ioan Marginean, Jason S. Page, Ryan T. Kelly, Keqi Tang, and Richard D. Smith<br/> An experimental study of pulsating electrosprays operated at subambient pressure is reported. The pressure domain that affords stable electrospray operation appears to be limited by the vapor pressure of the liquid. The voltage driving the electrospray is shown to have a logarithmic dependence on pr ... [Appl. Phys. Lett. 95, 184103 (2009)] published Fri Nov 6, 2009. Individual charge-trapping dislocations in an ionic insulator http://link.aip.org/link/?APL/95/184101/1&agg=rss Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, and Yuichi Ikuhara<br/> Insulating oxide materials find widespread technological applications where how their inside dislocations behave are known to influence or control performance. Here we demonstrate, by first-principles calculations on MgO, that individual dislocations can trap charges within empty space around their ... [Appl. Phys. Lett. 95, 184101 (2009)] published Thu Nov 5, 2009. The surface activation layer of GaAs negative electron affinity photocathode activated by Cs, Li, and NF http://link.aip.org/link/?APL/95/174109/1&agg=rss Y. Sun, R. E. Kirby, T. Maruyama, G. A. Mulhollan, J. C. Bierman et al.<br/> The lifetime of GaAs photocathodes can be greatly improved by introducing Li in the Cs+NF activation process. The surface activation layer of such photocathodes is studied by synchrotron radiation photoemission and is compared with GaAs photocathodes activated without Li. The charge distributions of ... [Appl. Phys. Lett. 95, 174109 (2009)] published Fri Oct 30, 2009. Correlation of O (1s) and Fe (2p) near edge x-ray absorption fine structure spectra and electrical conductivity of LaSrFeNiO http://link.aip.org/link/?APL/95/174108/1&agg=rss Selma Erat, Artur Braun, Alejandro Ovalle, Cinthia Piamonteze, Zhi Liu et al.<br/> A-site substitution of La by Sr in polaron conducting ABO-type perovskite LaSrFeNiO causes oxidation of Fe toward Fe and formation of conducting electron holes, as evidenced by Fe (2p) and O (1s) near edge x-ray absorption fine structure spectra. Hole doping is reflected by linear variation of the p ... [Appl. Phys. Lett. 95, 174108 (2009)] published Fri Oct 30, 2009. Improved model for the angular dependence of excimer laser ablation rates in polymer materials http://link.aip.org/link/?APL/95/174105/1&agg=rss J. E. A. Pedder, A. S. Holmes, and P. E. Dyer<br/> Measurements of the angle-dependent ablation rates of polymers that have applications in microdevice fabrication are reported. A simple model based on Beer's law, including plume absorption, is shown to give good agreement with the experimental findings for polycarbonate and SU8, ablated using the 1 ... [Appl. Phys. Lett. 95, 174105 (2009)] published Thu Oct 29, 2009. Resistance of diamond (100) to hyperthermal atomic oxygen attack http://link.aip.org/link/?APL/95/174106/1&agg=rss Z. Shpilman, I. Gouzman, E. Grossman, L. Shen, T. K. Minton et al.<br/> The morphology of polycrystalline chemical vapor deposited (CVD) diamond films following the interaction with hyperthermal (~5 eV) atomic oxygen (AO) was studied by atomic force microscopy. Selective etching of the (111) diamond facets occurred, while the (100) facets showed high endurance. The obs ... [Appl. Phys. Lett. 95, 174106 (2009)] published Thu Oct 29, 2009. Real time observation of partial dislocations in thin colloidal crystals http://link.aip.org/link/?APL/95/174107/1&agg=rss Yi-Yong Luo, Shu-Xin Hu, Ying Lu, Zhen-Hong Mai, and Ming Li<br/> We use laser diffraction microscopy to visualize in real time the motion of partial dislocations in thin colloidal crystals confined in flat capillaries. The results show that the formation of partial dislocation loops with their associated stacking faults is an energetically preferred strain-relaxa ... [Appl. Phys. Lett. 95, 174107 (2009)] published Thu Oct 29, 2009. Microwave energy absorption driven by dynamic structural and magnetization states in FeB metallic glass ribbons http://link.aip.org/link/?APL/95/174104/1&agg=rss R. Nicula, K. Ishizaki, M. Stir, J.-M. Catala-Civera, and S. Vaucher<br/> The kinetics of the microwave crystallization of FeB metallic glasses was investigated in situ using the time-resolved x-ray diffraction method. It is shown that the recorded thermal profile during the microwave exposure of the ribbons bears a close relationship with the dynamic magnetization state ... [Appl. Phys. Lett. 95, 174104 (2009)] published Thu Oct 29, 2009. Reversible hysteresis for broadband magnetopiezoelastic energy harvesting http://link.aip.org/link/?APL/95/174103/1&agg=rss Samuel C. Stanton, Clark C. McGehee, and Brian P. Mann<br/> We model and experimentally validate a nonlinear energy harvester capable of bidirectional hysteresis. In particular, both hardening and softening response within the quadratic potential field of a power generating piezoelectric beam (with a permanent magnet end mass) is invoked by tuning nonlinear ... [Appl. Phys. Lett. 95, 174103 (2009)] published Wed Oct 28, 2009.