scholarly journals Synchrotron Microbeam Diffraction Studies on the Alignment within 3D-Printed Smectic-A Liquid Crystal Elastomer Filaments during Extrusion

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 523
Author(s):  
Marianne E. Prévôt ◽  
Senay Ustunel ◽  
Benjamin M. Yavitt ◽  
Guillaume Freychet ◽  
Caitlyn R. Webb ◽  
...  

3D printing of novel and smart materials has received considerable attention due to its applications within biological and medical fields, mostly as they can be used to print complex architectures and particular designs. However, the internal structure during 3D printing can be problematic to resolve. We present here how time-resolved synchrotron microbeam Small-Angle X-ray Diffraction (μ-SAXD) allows us to elucidate the local orientational structure of a liquid crystal elastomer-based printed scaffold. Most reported 3D-printed liquid crystal elastomers are mainly nematic; here, we present a Smectic-A 3D-printed liquid crystal elastomer that has previously been reported to promote cell proliferation and alignment. The data obtained on the 3D-printed filaments will provide insights into the internal structure of the liquid crystal elastomer for the future fabrication of liquid crystal elastomers as responsive and anisotropic 3D cell scaffolds.

Soft Matter ◽  
2017 ◽  
Vol 13 (33) ◽  
pp. 5558-5568 ◽  
Author(s):  
Chao Yuan ◽  
Devin J. Roach ◽  
Conner K. Dunn ◽  
Quanyi Mu ◽  
Xiao Kuang ◽  
...  

We fabricate reversible shape changing soft actuators based on the hybrid 3D printing concept.


Author(s):  
Hongbo Wang ◽  
William S. Oates

A new class of glassy liquid crystal elastomers are studied to understand their light-coupled deformation characteristics. In particular, the photomechanics of azobenzene liquid crystal elastomers is modeled using a nonlinear continuum mechanics approach coupled with time-dependent liquid crystal domain structure evolution to understand light polarization effects on deformation. Light propagation and absorption within the elastomer is modeled using Maxwell’s electro-magnetic equations. By consideration of electric energy due to light absorption, light-induced electrical stresses are introduced which provide the driving force for mechanical deformation via coupling with the azobenzene liquid crystals. A liquid crystal director (i.e., orientation of the liquid crystal molecule) is used to describe liquid crystal evolution and elastomer deformation. This aspect of the model is extended to include 3D effects to accommodate trans-cis-trans photoisomerization. This is coupled to plane stress, nonlinear mechanics to demonstrate key field-coupled mechanics relations governing this class of smart materials. The results show that the model successfully predicts large, bi-directional bending of the polymer film by controlling the polarization of light. The results are consistent with recent experimental data given in the literature.


Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3128-3136
Author(s):  
Suzuka Okamoto ◽  
Shinichi Sakurai ◽  
Kenji Urayama

Stretching angle for a main-chain liquid crystal elastomer has pronounced effects on the width of the stress plateau as well as the ultimate elongation, while it has no effect on the plateau height.


Polymer ◽  
2018 ◽  
Vol 158 ◽  
pp. 96-102 ◽  
Author(s):  
Andraž Rešetič ◽  
Jerneja Milavec ◽  
Valentina Domenici ◽  
Blaž Zupančič ◽  
Alexey Bubnov ◽  
...  

2015 ◽  
Vol 3 (17) ◽  
pp. 4424-4430 ◽  
Author(s):  
Huihui Xing ◽  
Jun Li ◽  
Jinbao Guo ◽  
Jie Wei

The fabrication of inverse opal micropatterns based on liquid crystal elastomers with dual structural colors and their thermal switching behaviors are described.


2020 ◽  
Vol 22 (40) ◽  
pp. 23064-23072
Author(s):  
Andraž Rešetič ◽  
Jerneja Milavec ◽  
Valentina Domenici ◽  
Blaž Zupančič ◽  
Alexej Bubnov ◽  
...  

Orientational order parameter of magnetically aligned liquid crystal elastomer particles suspended in a cured silicone matrix is assessed using 2H-NMR spectroscopy. Obtained results correspond well with the composite's thermomechanical response.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5433
Author(s):  
Seung-Ho Shin ◽  
Jung-Hwa Lim ◽  
You-Jung Kang ◽  
Jee-Hwan Kim ◽  
June-Sung Shim ◽  
...  

The amount of photopolymer material consumed during the three-dimensional (3D) printing of a dental model varies with the volume and internal structure of the modeling data. This study analyzed how the internal structure and the presence of a cross-arch plate influence the accuracy of a 3D printed dental model. The model was designed with a U-shaped arch and the palate removed (Group U) or a cross-arch plate attached to the palate area (Group P), and the internal structure was divided into five types. The trueness and precision were analyzed for accuracy comparisons of the 3D printed models. Two-way ANOVA of the trueness revealed that the accuracy was 135.2 ± 26.3 µm (mean ± SD) in Group U and 85.6 ± 13.1 µm in Group P. Regarding the internal structure, the accuracy was 143.1 ± 46.8 µm in the 1.5 mm-thick shell group, which improved to 111.1 ± 31.9 µm and 106.7 ± 26.3 µm in the roughly filled and fully filled models, respectively. The precision was 70.3 ± 19.1 µm in Group U and 65.0 ± 8.8 µm in Group P. The results of this study suggest that a cross-arch plate is necessary for the accurate production of a model using 3D printing regardless of its internal structure. In Group U, the error during the printing process was higher for the hollowed models.


2020 ◽  
Vol 12 (25) ◽  
pp. 28692-28699 ◽  
Author(s):  
Morgan Barnes ◽  
Seyed M. Sajadi ◽  
Shaan Parekh ◽  
Muhammad M. Rahman ◽  
Pulickel M. Ajayan ◽  
...  

2021 ◽  
Vol 11 (5-S) ◽  
pp. 131-137
Author(s):  
Ahmar Khan ◽  
Mir Javid Iqbal ◽  
Saima Amin ◽  
Humaira Bilal ◽  
, Bilquees ◽  
...  

With the approval of first 3D printed drug “spritam” by USFDA, 3D printing is gaining acceptance in healthcare, engineering and other aspects of life. Taking 3D printing towards the next step gives birth to what is referred to as “4D printing”. The full credit behind the unveiling of 4D printing technology in front of the world goes to Massachusetts Institute of Technology (MIT), who revealed “time” in this technology as the fourth dimension.  4D printing is a renovation of 3D printing wherein special materials (referred to as smart materials) are incorporated which change their morphology post printing in response to a stimulus. Depending upon the applicability of this technology, there may be a variety of stimuli, most common among them being pH, water, heat, wind and other forms of energy.  The upper hand of 4D printing over 3D printing is that 3D printed structures are generally immobile, rigid and inanimate whereas 4D printed structures are flexible, mobile and able to interact with the surrounding environment based on the stimulus. This capability of 4D printing to transform 3D structures into smart structures in response to various stimuli promises a great potential for biomedical and bioengineering applications. The potential of 4D printing in developing pre-programmed biomaterials that can undergo transformations lays new foundations for enabling smart pharmacology, personalized medicine, and smart drug delivery, all of which can help in combating diseases in a smarter way. Hence, the theme of this paper is about the potential of 4D printing in creating smart drug delivery, smart pharmacology, targeted drug delivery and better patient compliance. The paper highlights the recent advancements of 4D printing in healthcare sector and ways by which 4D printing is doing wonders in creating smart drug delivery and tailored medicine. The major constraints in the approach have also been highlighted. Keywords: 4D printing, smart, drug delivery system, patient compliance, biomaterials, tailored medicine


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