Temperature tunable optical gratings in nematic elastomer

Multi‐Photon 4D Printing of Complex Liquid Crystalline Microstructures by In Situ Alignment Using Electric Fields

“…We emphasize that, in contrast to previously reported techniques, [7,8,[14][15][16]41,42,51] our approach does not rely on any surface-mediated alignment of the director and hence allows for arbitrary 3D spatial distribution of the director orientation within the printed 3D structures. Furthermore, our approach is not limited to cell heights of only a few tens of micrometers like previous approaches.…”

“…The ink contains the liquid crystal mixture E7. This mixture dissolves ordinary reactive mesogens [7,8,[14][15][16]41,42,52] such that the ink is in the nematic phase at room temperature. Furthermore, E7 helps to lower the electric field strength at which the Fréedericksz transition occurs.…”

“…Additive manufacturing of stimulusresponsive 3D microstructures, also referred to as 4D printing, is a frontier of materials research [1][2][3][4][5] with numerous potential applications in soft microrobotics, [6][7][8][9][10][11] time-dependent (spacetime) metamaterials, [12,13] optics, [14][15][16][17] and generally in active micro-and nanostructures. [18][19][20][21][22] In particular, repeatable large-amplitude actuation is desirable in response to conveniently accessible external stimuli such as temperature, [15][16][17][18][19][20]23] light intensity, [7,8,11,19,21] pH value, [18,20,24,25] magnetic fields, [9][10][11] etc. For many applications in the life sciences and in micro-fluidics, operation under aqueous conditions is desirable.…”

Thiol‐acrylate main‐chain liquid‐crystalline elastomers with tunable thermomechanical properties and actuation strain

“…The complex structure of LCEs enables several unique mechanical and optical properties; their most fascinating property is the ability to change their shape reversibly in response to external stimuli such as heat or light . Applications for such materials range from sensors and actuators for biological applications such as artificial muscles, biomimetic iris lenses, tunable optical gathering devices, cell scaffolds, microgrippers for robotics, microvalves for microfluidic systems, and organic solar cells …”

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

“…These materials can demonstrate extraordinary changes in shape, soft-elasticity behavior, and tunable optical properties in response to a stimulus such as heat or light, [1][2][3] which makes them suitable for many for potential technological applications such as artificial muscles, 4,5 sensors, 6 and actuators. 6,7 LCEs have already been demonstrated in many applications such as microgrippers for robotics, 8 micro-electromechanical systems (MEMS), 6,9 optical grating devices, 10 tunable apertures, 6,11 and microfluidic systems. 12 The structural components that give rise to the ordered LC phases are called mesogens.…”