scholarly journals Construction of invisibility cloaks of arbitrary shape and size using planar layers of metamaterials

2012 ◽  
Vol 111 (12) ◽  
pp. 123106 ◽  
Author(s):  
Oliver Paul ◽  
Yaroslav Urzhumov ◽  
Christoffer Elsen ◽  
David Smith ◽  
Marco Rahm
Keyword(s):  
Arbitrary Shape ◽  
Invisibility Cloaks ◽  
Shape And Size

scholarly journals Metal-Assisted Catalytic Etching (MACE) for Nanofabrication of Semiconductor Powders

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 776
Author(s):  
Kurt W. Kolasinski
Keyword(s):  
Arbitrary Shape ◽  
Metal Nanoparticle ◽  
Metal Catalyst ◽  
Spontaneous Deposition ◽  
Electroless Etching ◽  
Natural Tendency ◽  
Galvanic Deposition ◽  
Catalytic Etching ◽  
Nanostructured Powders ◽  
Shape And Size

Electroless etching of semiconductors has been elevated to an advanced micromachining process by the addition of a structured metal catalyst. Patterning of the catalyst by lithographic techniques facilitated the patterning of crystalline and polycrystalline wafer substrates. Galvanic deposition of metals on semiconductors has a natural tendency to produce nanoparticles rather than flat uniform films. This characteristic makes possible the etching of wafers and particles with arbitrary shape and size. While it has been widely recognized that spontaneous deposition of metal nanoparticles can be used in connection with etching to porosify wafers, it is also possible to produced nanostructured powders. Metal-assisted catalytic etching (MACE) can be controlled to produce (1) etch track pores with shapes and sizes closely related to the shape and size of the metal nanoparticle, (2) hierarchically porosified substrates exhibiting combinations of large etch track pores and mesopores, and (3) nanowires with either solid or mesoporous cores. This review discussed the mechanisms of porosification, processing advances, and the properties of the etch product with special emphasis on the etching of silicon powders.

scholarly journals Photolithographically Home-Made PVDF Sensor for Cavitation Impact Load Measurement

2020 ◽  
Vol 328 ◽  
pp. 01004
Author(s):  
Jan Hujer ◽  
Menghuot Phan ◽  
Tomáš Kořínek ◽  
Petra Dančová ◽  
Miloš Müller
Keyword(s):  
Cavitation Bubble ◽  
Arbitrary Shape ◽  
Printed Circuit Boards ◽  
Impact Load ◽  
Protective Layer ◽  
Circuit Boards ◽  
Load Measurement ◽  
Printed Circuit ◽  
Kapton Tape ◽  
Shape And Size

Piezoelectric PVDF sensors offer a unique option for the measurement of cavitation aggressiveness represented by the magnitude of impacts due to cavitation bubble collapses near walls. The aggressiveness measurement requires specific sensors shape and area, whereas commercial PVDF sensors are fabricated in limited geometry and size ranges. The photolithography method offers a possibility of production of home-made PVDF sensors of arbitrary shape and size. This paper deals with the calibration of a photolithographically home-made PVDF sensor for the cavitation impact load measurement. The calibration of sensors was carried out by the ball drop method. Sensors of different sizes were fabricated by the photolithography method from multi-purpose both side metallized PVDF sheet. The standard technology used for the fabrication of printed circuit boards was utilized. Commercial PVDF sensors of the same size were calibrated and the calibration results were compared with the home-made sensors. The effect of size and the effect of one added protective layer of Kapton tape on a sensor sensitivity were investigated.

scholarly journals Optical forces on particles of arbitrary shape and size

2007 ◽  
Vol 9 (8) ◽  
pp. S228-S234 ◽  
Author(s):  
Douglas Bonessi ◽  
Keith Bonin ◽  
Thad Walker
Keyword(s):  
Arbitrary Shape ◽  
Optical Forces ◽  
Shape And Size

scholarly journals Metal Assisted Catalytic Etching (MACE) for Nanofabrication of Semiconductor Powders

2021 ◽  
Author(s):  
Kurt W. Kolasinski
Keyword(s):  
Arbitrary Shape ◽  
Metal Nanoparticle ◽  
Metal Catalyst ◽  
Spontaneous Deposition ◽  
Electroless Etching ◽  
Natural Tendency ◽  
Galvanic Deposition ◽  
Catalytic Etching ◽  
Nanostructured Powders ◽  
Shape And Size

Electroless etching of semiconductors was elevated to an advanced micromachining process by the addition of a structured metal catalyst. Patterning of the catalyst by lithographic techniques facilitates the patterning of crystalline and polycrystalline wafer substrates. Galvanic deposition of metals on semiconductors has a natural tendency to produce nanoparticles rather than flat uniform films. This characteristic makes possible the etching of not only wafers but also particles with arbitrary shape. While it has been widely recognized that spontaneous deposition of metal nanoparticles can be used in connection with etching to porosify wafers, it is also possible to produced nanostructured powders. MACE can be controlled to produce (1) etch track pores with shapes and sizes closely related to the shape and size of the metal nanoparticle, (2) hierarchically porosified substrates exhibiting combinations of large etch track pores and mesopores, and (3) nanowires with either solid or mesoporous cores. This review discussed the mechanisms of porosification, processing advances and the properties of the etch product with special emphasis on the etching of silicon powders.

Product trial function for confined quantum systems

1995 ◽  
Vol 73 (1-2) ◽  
pp. 48-52 ◽  
Author(s):  
K. R. Brownstein
Keyword(s):  
Differential Equation ◽  
Quantum Well ◽  
Arbitrary Shape ◽  
Quantum Systems ◽  
Hydrogenic Impurity ◽  
Product Trial ◽  
Quantum Well Wire ◽  
Judicious Choice ◽  
Confined Quantum Systems ◽  
Shape And Size

To obtain the energy of a confined quantum system (e.g., a quantum-well wire) using the variational method, one usually uses a product ψ(r) = F(r)G(r) form for a trial wave function. The envelope function F takes care of the boundary condition (ψ = 0) by vanishing on the boundary of the confining region R while the function G can contain variational parameters for flexibility. We show that by judicious choice for F and G, the kinetic energy decouples into the sum of two terms: one associated with F and the other with G. For the particular case of a Coulomb potential (e.g., a hydrogenic impurity) we obtain (i) an expression for [Formula: see text] and (ii) a differential equation for the associated binding energy as a function of the size of the containing region R; both of these being valid for regions of arbitrary shape and size. A prediction of the differential equation is shown to agree with a published calculation for a quantum-well wire.

scholarly journals Coordinate transformations make perfect invisibility cloaks with arbitrary shape

2008 ◽  
Vol 10 (4) ◽  
pp. 043040 ◽  
Author(s):  
Wei Yan ◽  
Min Yan ◽  
Zhichao Ruan ◽  
Min Qiu
Keyword(s):  
Arbitrary Shape ◽  
Coordinate Transformations ◽  
Invisibility Cloaks
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