APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

20 Apr 2009

Volume 94, Issue 16, Articles (16xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 94, 161105 (2009); http://dx.doi.org/10.1063/1.3119666 (3 pages)

Artur R. Davoyan, Ilya V. Shadrivov, Andrey A. Sukhorukov, and Yuri S. Kivshar
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Self collimation of ultrasound in a three-dimensional sonic crystal

Ester Soliveres, Víctor Espinosa, Isabel Pérez-Arjona, Víctor J. Sánchez-Morcillo, and Kestutis Staliunas

Appl. Phys. Lett. 94, 164101 (2009); http://dx.doi.org/10.1063/1.3104861 (3 pages) | Cited 10 times

Online Publication Date: 21 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the experimental demonstration of self-collimation (subdiffractive propagation) of an ultrasonic beam inside a three-dimensional (3D) sonic crystal. The crystal is formed by two crossed steel cylinders structures in a woodpilelike geometry disposed in water. Measurements of the 3D field distribution show that a narrow beam, which diffractively spreads in the absence of the sonic crystal, is strongly collimated in propagation inside the crystal, demonstrating the 3D self-collimation effect.
Show PACS
43.35.-c Ultrasonics, quantum acoustics, and physical effects of sound
43.25.-x Nonlinear acoustics

Nonlinear oscillators for vibration energy harvesting

L. Gammaitoni, I. Neri, and H. Vocca

Appl. Phys. Lett. 94, 164102 (2009); http://dx.doi.org/10.1063/1.3120279 (3 pages) | Cited 33 times

Online Publication Date: 22 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Vibration to electricity energy conversion strategies are discussed by using nonlinear stochastic dynamics. General principles for the exploitation of nonlinear oscillators in energy harvesting that provide useful leads for the realization of micropower generators of practical interest are presented.
Show PACS
84.60.-h Direct energy conversion and storage
02.50.Fz Stochastic analysis

Characterization of microrod arrays by image analysis

Reinald Hillebrand, Silko Grimm, Reiner Giesa, Hans-Werner Schmidt, Klaus Mathwig, Ulrich Gösele, and Martin Steinhart

Appl. Phys. Lett. 94, 164103 (2009); http://dx.doi.org/10.1063/1.3122141 (3 pages)

Online Publication Date: 22 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The uniformity of the properties of array elements was evaluated by statistical analysis of microscopic images of array structures, assuming that the brightness of the array elements correlates quantitatively or qualitatively with a microscopically probed quantity. Derivatives and autocorrelation functions of cumulative frequency distributions of the object brightnesses were used to quantify variations in object properties throughout arrays. Thus, different specimens, the same specimen at different stages of its fabrication or use, and different imaging conditions can be compared systematically. As an example, we analyzed scanning electron micrographs of microrod arrays and calculated the percentage of broken microrods.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
02.50.-r Probability theory, stochastic processes, and statistics
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)

An analytical model for the wettability switching characteristic of a nanostructured thermoresponsive surface

Ghanashyam Londe, Anindarupa Chunder, Lei Zhai, and Hyoung J. Cho

Appl. Phys. Lett. 94, 164104 (2009); http://dx.doi.org/10.1063/1.3103270 (3 pages) | Cited 1 time

Online Publication Date: 23 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The applications of thermoresponsive surfaces require the development of a rigorous mathematical treatment for these surfaces to understand and improve their behavior. We propose an analytical model to describe the transfer characteristics (variation in contact angle versus temperature) of a unique nanostructured thermosensitive surface, consisting of silica nanoparticles and a hydrophilic/hydrophobic thermoresponsive polymer, poly(N-isopropylacrylamide). Three different thermo-sensitive platforms were fabricated and the contact angle change of a water droplet on the surface with varying surface temperature was analytically modeled.
Show PACS
68.08.Bc Wetting
68.03.Cd Surface tension and related phenomena
68.35.Md Surface thermodynamics, surface energies

On generation of picosecond inhomogeneous shear strain fronts by laser-induced gratings

Vitalyi Gusev

Appl. Phys. Lett. 94, 164105 (2009); http://dx.doi.org/10.1063/1.3125243 (3 pages) | Cited 3 times

Online Publication Date: 23 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The processes leading to excitation of inhomogeneous, plane compression/dilatation bulk acoustic strain pulses and shear bulk acoustic strain fronts following the creation of a transient laser interference pattern at a mechanically free surface of an elastically isotropic medium are described. It is shown that the characteristic frequencies of these acoustic disturbances can be much higher than those corresponding to the spatial period of the laser-induced grating. As well, it is shown that the inherent dispersive nature of these bulk acoustic eigenmodes provides plausible explanation for the reported observations of acoustic echo transformation in thin film, ultrafast laser ultrasonics experiments.
Show PACS
43.35.Ud Thermoacoustics, high temperature acoustics, photoacoustic effect
42.79.Dj Gratings
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Detection of fluorescently labeled biomolecules immobilized on a detachable substrate using an integrated amorphous silicon photodetector

A. C. Pimentel, A. T. Pereira, D. M. F. Prazeres, V. Chu, and J. P. Conde

Appl. Phys. Lett. 94, 164106 (2009); http://dx.doi.org/10.1063/1.3122345 (3 pages) | Cited 2 times

Online Publication Date: 23 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An integrated platform for biomolecular detection is described comprising two parts: (1) an a-Si:H p-i-n photodiode with an integrated filter for fluorescence detection, and (2) a detachable layer (a glass slide) where the biological molecular recognition reaction takes place. The distance between the photodetector and the layer with the fluorescently labeled biomolecules must be accurately controlled to ensure adequate sensitivity. A spacer 400 μm thick was used to separate the photodetector from the molecular layer. The minimum surface density of quantum dot Evitag 604 nm detected was 8 fmol/cm2. The detection of an antibody-antigen molecular recognition reaction is presented.
Show PACS
87.80.-y Biophysical techniques (research methods)
87.15.km Protein-protein interactions
87.15.R- Reactions and kinetics
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors

Droplet formation and stability of flows in a microfluidic T-junction

Amit Gupta, S. M. Sohel Murshed, and Ranganathan Kumar

Appl. Phys. Lett. 94, 164107 (2009); http://dx.doi.org/10.1063/1.3116089 (3 pages) | Cited 17 times

Online Publication Date: 23 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Flow regimes obtained as a consequence of two immiscible fluids interacting at a T-junction are presented for high Capillary numbers and different flow rates of the continuous and dispersed phases. Through lattice Boltzmann based simulations, a regime map is created that distinguishes parallel flows from droplet flows. Simulations show the dependence of flow rates and viscosity ratio on the volume of droplets formed, which is compared with existing experimental data. At high Capillary numbers, the transition zone which separates parallel and droplet flows shrinks, and is influenced by the viscosity ratio as well.
Show PACS
47.55.D- Drops and bubbles
47.11.Qr Lattice gas
47.20.-k Flow instabilities
47.61.-k Micro- and nano- scale flow phenomena
47.55.N- Interfacial flows

Multiple magnetic microrobot control using electrostatic anchoring

Chytra Pawashe, Steven Floyd, and Metin Sitti

Appl. Phys. Lett. 94, 164108 (2009); http://dx.doi.org/10.1063/1.3123231 (3 pages) | Cited 8 times

Online Publication Date: 23 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Addressing power and control to individual untethered microrobots is a challenge for small-scale robotics. We present a 250×130×100 μm3 magnetic robot wirelessly driven by pulsed external magnetic fields. An induced stick-slip motion results in translation speeds over 8 mm/s. Control of multiple robots is achieved by an array of addressable electrostatic anchoring pads on the surface, which selectively fixes microrobots, preventing translation. We demonstrate control of two microrobots in both uncoupled individual motion and coupled symmetric motion. An estimated anchoring force of 23.0 μN is necessary to effectively fix each microrobot.
Show PACS
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
07.07.Tw Servo and control equipment; robots

Electrowetting on polymer dispersed liquid crystal

Shih-Kang Fan, Cheng-Pu Chiu, and Jing-Wei Lin

Appl. Phys. Lett. 94, 164109 (2009); http://dx.doi.org/10.1063/1.3125253 (3 pages) | Cited 5 times

Online Publication Date: 24 April 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polymer dispersed liquid crystal (PDLC) is used as a dielectric layer in electrowetting. By applying voltage between a liquid droplet and the electrode underlying PDLC, electrowetting occurs at the liquid/PDLC interface accompanied with electro-optic responses of the reoriented LC droplets embedded in PDLC. Two basic experiments investigating the electrowetting by sessile water droplets and the electro-optic effects through squeezed water droplets were design and performed. The basic functions of a liquid lens and droplet manipulations, including transporting, splitting, and merging, were demonstrated.
Show PACS
61.30.Hn Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions
68.08.Bc Wetting
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close