Photopolymerization-triggered molecular movement for versatile liquid crystal show


TOKYO, Nov. 10, 2017 /PRNewswire/ Scientists at Tokyo Institute of Technology (Tokyo Tech) and McGill University have developed a brand new dye-free photoalignment technique that allows 2D patterns of liquid crystals in a single step by guiding nonpolarized mild temporally and spatially on the photopolymerization course of. This new technique gives a pathway for the easy creation of extremely purposeful natural supplies resembling versatile liquid crystal gadgets.

With present 2D methods, one usually irradiates a liquid crystal movie that accommodates added photoresponsive dye molecules, with uniform polarized mild. This controls the online liquid crystal alignment through the interplay of the dye dipole and the polarization axis of sunshine. The downside with these programs is the necessity for including sturdy dyes, which may discolor or degrade optical and stability properties. Thus, a dye-free technique is extremely desired within the engineering business.

Currently, solely two approaches to dye-free strategies have been explored. The first is a two-step alignment technique, wherein the liquid crystal supplies are coated over a really skinny dye-containing photoalignment layer after which aligned or mounted by polymerization. While this technique has confirmed very profitable in reaching stimuli-responsive 2D aligned liquid crystals and elastomers utilized in photonics, photo voltaic power harvesting, microfluidics, and soft-robotic gadgets, it’s costly and time-consuming. The creation of a movie with microscopic arrays of microalignment patterns requires exact and dynamic management of the polarized course of incident mild in every pixel, so this technique is unsuitable for aligning patterns on the nanoscale over mbadive areas.

The second method to the event of a dye-free system makes use of floor topography to beat the constraints of typical photoalignment. In this technique, the liquid crystals are aligned over a floor topography template by means of lithography, nanoimprinting, or inkjet methods amongst others. While this technique permits for 2D micropatterning of molecular alignment, it nonetheless requires multi-step processing, making it expensive and time-consuming. Due to the floor roughness from the topographic templates, this technique proves troublesome within the manufacturing of skinny movies.

A badysis group led by Atsushi Shishido at Tokyo Tech has reported the event of a brand new technique of scanning wave photopolymerization that makes use of spatial and temporal scanning of centered guided mild. As the polymerization response proceeds, a mbad stream within the movie is triggered, and this ends in alignment of the liquid crystals with the incident mild patterns. The desired alignment is achieved by means of a single step by mild triggered mbad stream.

This new technique generates arbitrary alignment patterns with superb management over bigger areas in all kinds of liquid crystal supplies with out the necessity for sturdy dyes or further processing steps, one thing that earlier strategies had been unable to realize. This technique has the extra benefit of limitless complexity in 2D patterns that might, in principal, solely be restricted by the sunshine diffraction limits.

This new idea of scanning wave photopolymerization is at present restricted to photopolymerizable liquid crystal programs with a thickness beneath tens of micrometers. However, additional investigation can develop materials programs that might be used resembling nanorods, nanocarbons, and proteins. Scanning wave photopolymerization will be readily launched into present photoproduction amenities, permitting for excellent financial benefits. The scientists at Tokyo Institute of Technology see this technique as a robust pathway for the easy creation of extremely purposeful natural supplies with arbitrary, superb molecular alignment patterns on the nanoscale over mbadive areas.



Kyohei Hisano 1, Miho Aizawa 1, Masaki Ishizu 1, Yosuke Kurata 1, Wataru Nakano 1, Norihisa Akamatsu 1, Christopher J. Barrett 1,2, and Atsushi Shishido 1,three ,*

Title of authentic paper:

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


Science Advances




1Laboratory for Chemistry and Life Sciences, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan

2Department of Chemistry, McGill University, Montreal, Quebec, Canada

3Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 7, Gobancho, Chiyodaku, Tokyo,102-0076,Japan

*Corresponding authors e-mail: [email protected]

About Tokyo Institute of Technology

Tokyo Institute of Technology stands on the forefront of badysis and better training because the main college for science and expertise in Japan. Tokyo Tech researchers excel in a wide range of fields, resembling materials science, biology, laptop science and physics. Founded in 1881, Tokyo Tech has grown to host 10,000 undergraduate and graduate college students who change into principled leaders of their fields and a number of the most sought-after scientists and engineers at high corporations. Embodying the Japanese philosophy of “monotsukuri,” that means technical ingenuity and innovation, the Tokyo Tech neighborhood strives to make vital contributions to society by means of high-impact badysis.


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