Laser processing of microdroplet structure of liquid crystal in 3D

Abstract

Processing of mesoscale structures of soft matter and liquid is of great importance in both science and engineering. In this work, we introduce the concept of laser-assisted micromachining to this field and inject a certain number of microdroplets into a preselected location on the surface of a liquid crystal drop through laser irradiation. The impact of laser energy on the triggered injection is discussed. The sequentially injected microdroplets are spontaneously captured by the defect ring in the host drop and transported along this defect track as micro-cargos. By precisely manipulating the laser beam, the tailored injection of droplets is achieved, and the injected droplets self-assemble into one necklace ring within the host drop. The result provides a bottom-up approach for the in-situ and three-dimensional microfabrication of droplet structure of soft matter using a laser beam, which may be applicable in the development of optical and photonic devices.

Production and Reconfiguration of Double Emulsions by Temperature Control

“…The TAMI phenomenon is caused by the thermally induced Marangoni effect. Laser-induced water injection across the LC–water interface, introduced by the photothermally controlled Marangoni effect, has been studied in previous works. – , It has been demonstrated that the injection site is determined by the laser irradiation area, where a sufficient temperature gradient is established. To understand the temperature distribution introduced by the TAMI method, we perform a FEM simulation (see Materials and Methods).…”

“…21,22 With the help of the elasticity of the LC molecules, the injected solution spontaneously forms into monodispersed guest droplets which latter self-assemble into substructures along the director field of the host LC droplet. 20,21,23 However, this approach requires an external laser system. Producing MDEs at low cost and high rates remains challenging.…”

“…Unfortunately, most of these brilliant methods can only be applied to generate single-core double emulsions. In our previous studies, we reported a laser micromachining approach for assembling a single multicore double emulsion (MDE) droplet with controlled substructures. , Specifically, the laser beam acts as a localized heat source to introduce a photothermally controlled Marangoni effect around a liquid crystal (LC, oil-like) emulsion droplet, leading to instabilities on its interface that result in the injection of the surrounding solution. , With the help of the elasticity of the LC molecules, the injected solution spontaneously forms into monodispersed guest droplets which latter self-assemble into substructures along the director field of the host LC droplet. ,, However, this approach requires an external laser system. Producing MDEs at low cost and high rates remains challenging.…”

Laser Injection Technique for Liquid Crystal Droplets with Arbitrary Shape

“…In addition, the Laser injection technique brings the concept of laser micro-nano manufacturing to the field of soft matter and injects water droplets into an LC droplet using a laser beam. [2][3][4] As the director field of the LC droplet is stabilized, the injected water droplets will self-assemble into an organized structure. But it requires a dedicated laser system and the processing efficiency is relatively low due to its serial nature.…”

Tunable terajets formed by core-shell microspheres for high-resolution terahertz zoom imaging

“…Within the visible light band, the feasibility of core-shell microspheres to form ultra-long photonic nanojets has been demonstrated 14 , inspiring our endeavor to apply this structure in THz band. Moreover, the progress in microfabrication technology expands the horizons for creating core-shell microspheres [15][16][17][18] . This study initially confirms the capability of core-shell microspheres to produce long terajets.…”