Block-like electroactive oligo(aniline)s: anisotropic structures with anisotropic function

2012 ◽  
Vol 22 (32) ◽  
pp. 16230 ◽  
Author(s):  
Zhecheng Shao ◽  
Zai Yu ◽  
Jianchen Hu ◽  
Saravanan Chandrasekaran ◽  
David M. Lindsay ◽  
...  
Keyword(s):  
Anisotropic Structures ◽  
Anisotropic Function

New polarized-light microscope for fast and orientation independent measurement of birefringent fine structure

1993 ◽  
Vol 51 ◽  
pp. 82-83
Author(s):  
Rudolf Oldenbourg
Keyword(s):  
Light Microscope ◽  
Polarized Light ◽  
Video Camera ◽  
Limited Range ◽  
Image Point ◽  
Computer Assisted ◽  
Optical Modulators ◽  
Anisotropic Structures ◽  
Long Time ◽  
Computer Assisted Image

The polarized light microscope has the unique potential to measure submicroscopic molecular arrangements dynamically and non-destructively in living cells and other specimens. With the traditional pol-scope, however, single images display only those anisotropic structures that have a limited range of orientations with respect to the polarization axes of the microscope. Furthermore, rapid measurements are restricted to a single image point or single area that exhibits uniform birefringence or other form of optical anisotropy, while measurements comparing several image points take an inordinately long time.We are developing a new kind of polarized light microscope which combines speed and high resolution in its measurement of the specimen anisotropy, irrespective of its orientation. The design of the new pol-scope is based on the traditional polarized light microscope with two essential modifications: circular polarizers replace linear polarizers and two electro-optical modulators replace the traditional compensator. A video camera and computer assisted image analysis provide measurements of specimen anisotropy in rapid succession for all points of the image comprising the field of view.

scholarly journals Getting grip in changing environments: the effect of friction anisotropy inversion on robot locomotion

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Halvor T. Tramsen ◽  
Lars Heepe ◽  
Jettanan Homchanthanakul ◽  
Florentin Wörgötter ◽  
Stanislav N. Gorb ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Legged Locomotion ◽  
Hexapod Robot ◽  
Friction Anisotropy ◽  
Anisotropic Friction ◽  
Walking Behavior ◽  
Robot Locomotion ◽  
Computational Morphology ◽  
Anisotropic Structures ◽  
Walking Environment

AbstractLegged locomotion of robots can be greatly improved by bioinspired tribological structures and by applying the principles of computational morphology to achieve fast and energy-efficient walking. In a previous research, we mounted shark skin on the belly of a hexapod robot to show that the passive anisotropic friction properties of this structure enhance locomotion efficiency, resulting in a stronger grip on varying walking surfaces. This study builds upon these results by using a previously investigated sawtooth structure as a model surface on a legged robot to systematically examine the influences of different material and surface properties on the resulting friction coefficients and the walking behavior of the robot. By employing different surfaces and by varying the stiffness and orientation of the anisotropic structures, we conclude that with having prior knowledge about the walking environment in combination with the tribological properties of these structures, we can greatly improve the robot’s locomotion efficiency.

scholarly journals Anisotropic dielectric susceptibility matrix of anisotropic medium

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wanrong Gao
Keyword(s):  
Light Scattering ◽  
Anisotropic Medium ◽  
Polarized Light ◽  
Scattering Matrix ◽  
Dielectric Susceptibility ◽  
Anisotropic Dielectric ◽  
New Methods ◽  
Mueller Matrices ◽  
Anisotropic Structures ◽  
The Fourier Transform

AbstractIn this work, we introduce the concept of anisotropic dielectric susceptibility matrix of anisotropic medium for both nondepolarizing and depolarizing medium. The concept provides a new way of analyzing light scattering properties of anisotropic media illuminated by polarized light. The explicit expressions for the elements of the scattering matrix are given in terms of the elements of the Fourier transform of the anisotropic dielectric susceptibility matrix of the medium. Finally, expressions for the elements of the Jones matrix of a thin layer of a deterministic anisotropic medium and the elements of the Mueller matrix of a depolarizing medium are given. The results obtained in this work is helpful for deriving information about the correlated anisotropic structures in depolarizing media from measured Mueller matrices. The findings in this work may also well prove stimulating to researchers working on new methods for analyzing light scattering properties.

scholarly journals Design and Characterization of Microscale Auxetic and Anisotropic Structures Fabricated by Multiphoton Lithography

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 446
Author(s):  
Ioannis Spanos ◽  
Zacharias Vangelatos ◽  
Costas Grigoropoulos ◽  
Maria Farsari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Performance ◽  
Element Analysis ◽  
Mechanical Responses ◽  
Multiphoton Lithography ◽  
Anisotropic Structures ◽  
Scanning Electron

The need for control of the elastic properties of architected materials has been accentuated due to the advances in modelling and characterization. Among the plethora of unconventional mechanical responses, controlled anisotropy and auxeticity have been promulgated as a new avenue in bioengineering applications. This paper aims to delineate the mechanical performance of characteristic auxetic and anisotropic designs fabricated by multiphoton lithography. Through finite element analysis the distinct responses of representative topologies are conveyed. In addition, nanoindentation experiments observed in-situ through scanning electron microscopy enable the validation of the modeling and the observation of the anisotropic or auxetic phenomena. Our results herald how these categories of architected materials can be investigated at the microscale.

scholarly journals Anisotropic, Wrinkled, and Crack-Bridging Structure for Ultrasensitive, Highly Selective Multidirectional Strain Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Heng Zhang ◽  
Dan Liu ◽  
Jeng-Hun Lee ◽  
Haomin Chen ◽  
Eunyoung Kim ◽  
...  
Keyword(s):  
Rational Design ◽  
Full Range ◽  
Human Motion ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Trade Off ◽  
Human Motion Detection ◽  
Sensing Applications ◽  
Anisotropic Structures

AbstractFlexible multidirectional strain sensors are crucial to accurately determining the complex strain states involved in emerging sensing applications. Although considerable efforts have been made to construct anisotropic structures for improved selective sensing capabilities, existing anisotropic sensors suffer from a trade-off between high sensitivity and high stretchability with acceptable linearity. Here, an ultrasensitive, highly selective multidirectional sensor is developed by rational design of functionally different anisotropic layers. The bilayer sensor consists of an aligned carbon nanotube (CNT) array assembled on top of a periodically wrinkled and cracked CNT–graphene oxide film. The transversely aligned CNT layer bridge the underlying longitudinal microcracks to effectively discourage their propagation even when highly stretched, leading to superior sensitivity with a gauge factor of 287.6 across a broad linear working range of up to 100% strain. The wrinkles generated through a pre-straining/releasing routine in the direction transverse to CNT alignment is responsible for exceptional selectivity of 6.3, to the benefit of accurate detection of loading directions by the multidirectional sensor. This work proposes a unique approach to leveraging the inherent merits of two cross-influential anisotropic structures to resolve the trade-off among sensitivity, selectivity, and stretchability, demonstrating promising applications in full-range, multi-axis human motion detection for wearable electronics and smart robotics.

Sol-gel synthesis of textured lanthanum titanate thin films

2003 ◽  
Vol 18 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Mary M. Sandstrom ◽  
Paul Fuierer
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Optical Measurements ◽  
Layered Perovskite ◽  
Orientation Factor ◽  
Anisotropic Structures ◽  
Sol Gel Films ◽  
Sol Gel Synthesis

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.

Impact location estimation in anisotropic structures

2015 ◽  
Author(s):  
Jingru Zhou ◽  
V. John Mathews ◽  
Daniel O. Adams
Keyword(s):  
Location Estimation ◽  
Impact Location ◽  
Anisotropic Structures
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