scholarly journals Orientation of Liquid Crystalline Molecules on PDMS Surfaces and within PDMS Microfluidic Systems

2021 ◽  
Vol 11 (24) ◽  
pp. 11593
Author(s):  
Szymon Baczyński ◽  
Piotr Sobotka ◽  
Kasper Marchlewicz ◽  
Mateusz Słowikowski ◽  
Marcin Juchniewicz ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Experimental Investigations ◽  
Microfluidic Systems ◽  
Crystalline Materials ◽  
Molecular Arrangement ◽  
Significant Barrier ◽  
Optical Applications ◽  
Manufacturing Technologies ◽  
Liquid Crystalline Materials ◽  
Orientation Of Molecules

The unique components of PDMS-based microfluidic systems are those combined with liquid crystalline materials. Their functionality, especially when it comes to optical applications, highly depends on the LC molecular arrangement. This work summarizes experimental investigations on the orientation of molecules within LC:PDMS structures according to the manufacturing technologies. The availability of high-quality molds to pattern PDMS is a significant barrier to the creation of advanced microfluidic systems. The possibility of using inexpensive molds in the rapid and reproducible fabrication process has been particularly examined as an alternative to photolithography. Different geometries, including an innovative approach for the electrical control of the molecular arrangement within PDMS microchannels, are presented. These studies are critical for novel optofluidic systems, introducing further research on LC:PDMS waveguiding structures.

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

Designing Chemically Selective Liquid Crystalline Materials that Respond to Oxidizing Gases

2021 ◽  
Author(s):  
Nanqi Bao ◽  
Jake Gold ◽  
Tibor Szilvasi ◽  
Huaizhe Yu ◽  
Robert Twieg ◽  
...  
Keyword(s):  
Computational Methods ◽  
First Principles ◽  
Liquid Crystalline ◽  
Soft Materials ◽  
Crystalline Materials ◽  
Liquid Crystalline Materials ◽  
Chemically Selective ◽  
Kinetics Of

Computational methods can provide first-principles insights into the thermochemistry and kinetics of reactions at interfaces, but this capability has not been widely leveraged to design soft materials that respond selectively...

Orthoconic antiferroelectric liquid crystalline materials

2005 ◽  
Vol 72 (9) ◽  
pp. 655
Author(s):  
K. Czuprynski ◽  
J. Gasowska ◽  
M. Tykarska ◽  
P. Kula ◽  
E. Sokól ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Crystalline Materials ◽  
Liquid Crystalline Materials
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