Scanning wave photopolymerization enables dye-free alignment patterning of liquid crystals

Hisano, Kyohei; Aizawa, Miho; Ishizu, Masaki; Kurata, Yosuke; Nakano, Wataru; Akamatsu, Norihisa; Barrett, Christopher J.; Shishido, Atsushi

doi:10.1126/sciadv.1701610

Cited by 62 publications

(43 citation statements)

References 68 publications

(86 reference statements)

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“…Acrylate‐based LCEs (homopolymers, aza‐Michael, and CTA chemistries, among others) have been prepared via surface‐enforced alignment via photopatterned surfaces. The arbitrary and complex organization of the LCEs facilitate directional strain in the material system, and can enable out‐of‐plane actuation upon thermal stimulus . The thermomechanical output of the epoxy‐based LCE that are the focus of this examination are compared to CnM‐CTA LCEs.…”

Section: Resultsmentioning

confidence: 99%

Microstructured Photopolymerization of Liquid Crystalline Elastomers in Oxygen‐Rich Environments

McCracken

Tondiglia

Auguste

et al. 2019

Adv Funct Materials

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Liquid crystal elastomers (LCEs) are soft materials that undergo large anisotropic shape change in response to stimuli. Rational organization of the local director field can impart spatial control of the strain profile, enabling stretch-based deformation capable of nearly 20 J kg −1 of output force. LCEs are increasingly being considered in end-use applications in robotics, therapeutics, and optics. Here, a new synthetic approach is introduced to prepare LCEs composed of main chain mesogens via the cationic photopolymerization of the epoxy liquid crystal monomer (LCM). This examination details the optical, mechanical, and thermal properties of epoxide-based LCEs as a function of spacer length (3, 6, or 11 carbons). The oxygen insensitivity of the cationic photopolymerization of these monomers makes this approach particularly attractive for implementation with emerging additive manufacturing techniques. This contribution focuses on microstructuring LCEs via 2-photon direct laser writing (2P-DLW). A custom heated cell facilitated 2P-DLW of the aligned LCE epoxy resin melts to fabricate diverse geometric arrays. Enabled by the orthogonality of the reaction chemistry, hybrid and microstructured material compositions are prepared via the encapsulation of LCE epoxy micropatterns with free-radical polymerization of acrylate-based LCEs. The distinct thermomechanical response of the hybridized and microstructured LCE composites enables local and spatially controlled actuation.

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Section: Resultsmentioning

confidence: 99%

Microstructured Photopolymerization of Liquid Crystalline Elastomers in Oxygen‐Rich Environments

McCracken

Tondiglia

Auguste

et al. 2019

Adv Funct Materials

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“…As a result, the intensities of the UCNP photoluminescence lines nonlinearly depend on the intensity of the incident NIR light. The general rule can be written as Iem ~ [Iex]n where n is the number of NIR quanta involved in the upconversion process [26].…”

Section: Resultsmentioning

confidence: 99%

Polymerization Assisted by Upconversion Nanoparticles under NIR Light

et al. 2019

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Photopolymerization of nanocomposite materials using near infrared light is one of the unique technologies based on the luminescent properties of lanthanide-doped upconversion nanoparticles (UCNPs). We explored the UCNP-triggered radical polymerization both in oligomer bulk and on the nanoparticle surface in aqueous dispersion. Core/shell UCNPs NaYF4:Yb3+ and Tm3+/NaYF4 with emitting lines in the ultraviolet and blue regions were used to activate a photoinitiator. The study of the bulk photopolymerization in an initially homogeneous reaction mixture showed the UCNP redistribution due to gradient density occurring in the volume, which led to formation of UCNP superlattices and spheres “frozen” in a polymer matrix. We also developed a strategy of “grafting from” the surface, providing polymer shell growth directly on the nanoparticles. The photosensitization of the endogenous water-soluble photoinitiator riboflavin by the resonance energy transfer from UCNPs was demonstrated in the course of monomer glycidyl methacrylate polymerization followed by photocrosslinking with poly(ethylene glycol) diacrylate on the nanoparticle surface.

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“…Furthermore, the materials mentioned so far are limited to simple soft matters such as polymers and colloids. In recent years, there has been new developments in the transport phenomena of liquid crystal under out of equilibrium condition, from temperature gradient (Oswald and Dequidt 2008;Yoshioka and Araoka 2018) to light-induced polymerization (Hisano et al 2017). Extensive study will further open this new field for the realization of functional devices as inspired by biological molecular motors in future.…”

Section: Discussionmentioning

confidence: 99%

Opto-thermal diffusiophoresis of soft biological matter: from physical principle to molecular manipulation

Fukuyama

Maeda

2020

Biophys Rev

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Transport of ions and molecules under external field gradients is fundamental phenomena relevant to many biological systems including molecular motors in nature. As inspired from such biological transport, novel optical manipulation by using local solute gradient and the creation of self-propulsive particles are being developed using this technology. In this review article, we describe the basic principles behind those transport phenomena under a temperature and a solute concentration gradient and discuss novel manipulation tools for soft biological materials. The control of such micron-scale transport will bring new insight in design principles of functional materials showing autonomous motion as seen in molecular motors.

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Scanning wave photopolymerization enables dye-free alignment patterning of liquid crystals

Abstract: Liquid crystals are 2D patterned with nonpolarized light by a new dye-free photoalignment method.

Cited by 62 publications

References 68 publications

Microstructured Photopolymerization of Liquid Crystalline Elastomers in Oxygen‐Rich Environments

Microstructured Photopolymerization of Liquid Crystalline Elastomers in Oxygen‐Rich Environments

Polymerization Assisted by Upconversion Nanoparticles under NIR Light

Opto-thermal diffusiophoresis of soft biological matter: from physical principle to molecular manipulation

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