Low-Voltage-Driven Actuators Using Photo-Cross-Linked Ionic Columnar Liquid-Crystalline Polymer Films

Abstract

Liquid-crystalline molecular self-assembly has become an attractive strategy to enhance mass transport and mechanical strength. Herein we report low-voltage-driven actuators based on photo-cross-linked ionic columnar liquidcrystalline polymer films integrating ionic liquids into nanoscale 1D channels. We have unveiled the effect of nanochannels on the actuator performance. The nanostructured actuator exhibits larger deformation and generated force compared with the corresponding amorphous actuator. The concept of nanosegregation consisting of liquid and anisotropic rigid domains will open up a promising pathway for electroactive actuator design.

Electroactive Soft Actuators Based on Columnar Ionic Liquid Crystal/Polymer Composite Membrane Electrolytes Forming 3D Continuous Ionic Channels

“…While the 50 μm thick actuator showed no detectable force, the thicker actuator with the total thickness of 160 μm (146 μm thick ZI/IL/PVA composite film and 7 μm thick PEDOT:PSS film) successfully generated a blocking force of 0.27 mN under DC 2 V in 70% RH (Figure S26 in the Supporting Information). This value of 3D continuous composite actuator is comparable to that of the photo-cross-linked ionic columnar liquid-crystalline polymer actuator forming 1D ionic channels (0.28 mN under DC 2 V, the total thickness of 61 μm) …”

“…This value of 3D continuous composite actuator is comparable to that of the photo-crosslinked ionic columnar liquid-crystalline polymer actuator forming 1D ionic channels (0.28 mN under DC 2 V, the total thickness of 61 μm). 45 As the ZI/IL/PVA-based actuator shows good actuation but low stress output, we thought that this actuator may be suitable for adaptive optics and light focusing application. The ZI/IL/ PVA-based actuator laminated with an aluminum-deposited poly(ethylene telephthalate) film has found to act as a lowvoltage driven, large-stroke deformable mirror (Figure S27 in the Supporting Information).…”

“…41−44 Recently, we have succeeded in developing ionic electromechanical nanostructured polymer actuators using photo-cross-linked ionic columnar liquidcrystalline polymer films integrating ionic liquids into onedimensional nanochannels. 45 The nanostructured actuator exhibited larger deformation and generated force compared with the corrensponding amorphous actuator. 45 However, current anisotropic liquid-crystalline electrolytes provide limited efficiency due to the inhibition of ion migration at the multidomain grain boundaries, although many efforts have been conducted to achieve macroscopically oriented monodomains such as surface treatments and magnetic fields.…”

“…45 The nanostructured actuator exhibited larger deformation and generated force compared with the corrensponding amorphous actuator. 45 However, current anisotropic liquid-crystalline electrolytes provide limited efficiency due to the inhibition of ion migration at the multidomain grain boundaries, although many efforts have been conducted to achieve macroscopically oriented monodomains such as surface treatments and magnetic fields. 46 More recently, we and other groups have focused on bicontinuous cubic liquid-crystalline electrolytes due to their intrinsic 3D channel connectivity.…”

“…The use of liquid crystal self-assembly is a powerful approach for the preparation of nanostructured soft materials exhibiting low-dimensional transport of ions. − We previously reported enhanced ion transport for nanostructured ionic liquid crystals and ordered ionic liquids into hydrogen-bonded liquid crystal networks, wherein ions can form 1–3D nanochannels shielded by insulating mesogenic moieties. , These materials have great potential as electrolytes in energy devices such as lithium-ion batteries, fuel cells, and dye-sensitized solar cells. − Recently, we have succeeded in developing ionic electromechanical nanostructured polymer actuators using photo-cross-linked ionic columnar liquid-crystalline polymer films integrating ionic liquids into one-dimensional nanochannels . The nanostructured actuator exhibited larger deformation and generated force compared with the corrensponding amorphous actuator . However, current anisotropic liquid-crystalline electrolytes provide limited efficiency due to the inhibition of ion migration at the multidomain grain boundaries, although many efforts have been conducted to achieve macroscopically oriented monodomains such as surface treatments and magnetic fields .…”