Dissertations / Theses on the topic 'Liquid crystalline elastomer'

Thesis (Doctor of Philosophy)--Case Western Reserve University, 2010
Department of Macromolecular Science and Engineering Title from PDF (viewed on 2010-05-25) Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center

This dissertation demonstrates the design of reversibly self-morphing novel liquid crystalline elastomer (LCE) antennas that can dynamically change electromagnetic performance in response to temperature. This change in performance can be achieved by programming the shape change of stimuli-responsive (i.e., temperature-responsive) LCEs, and using these materials as substrates for reconfigurable antennas. Existing reconfigurable antennas rely on external circuitry such as Micro-Electro-Mechanical-Systems (MEMS) switches, pin diodes, and shape memory alloys (SMAs) to reconfigure their performance. Antennas using MEMS or diodes exhibit low efficiency due to the losses from these components. Also, antennas based on SMAs can change their performance only once as SMAs response to the stimuli and is not reversible. Flexible electronics are capable of morphing from one shape to another using various techniques, such as liquid metals, hydrogels, and shape memory polymers. LCE antennas can reconfigure their electromagnetic performance, (e.g., frequency of operation, polarization, and radiation pattern) and enable passive (i.e., battery-less) temperature sensing and monitoring applications, such as passive radio frequency identification device (RFID) sensing tags. Limited previous work has been performed on shape-changing antenna structures based on LCEs. To date, self-morphing flexible electronics, including antennas, which rely on stimuli-responsive LCEs that reversibly change shape in response to temperature changes, have not been previously explored. Here, LCE antennas will be studied and developed. Also, the metallization of LCEs with different metal conductors and their fabrication process, by either electron beam (E-Beam) evaporation or optical gluing of the metal film will be observed. The LCE material can have a significant impact on sensing applications due to its reversible actuation that can enable a sensor to work repeatedly. This interdisciplinary research (material polymer science and electrical engineering) is expected to contribute to the development of morphing electronics, including sensors, passive antennas, arrays, and frequency selective surfaces (FSS).

Soft materials have attracted much scientific and technical interest in recent years. In this thesis, attention has been placed on the underpinning relations between molecular structure and properties of one type of soft matter - main chain liquid crystalline elastomers (MCLCEs), which may have application as shape memory or as auxetic materials. In this work, a number of siloxane-based MCLCEs and their linear polymer analogues (MCLCPs) with chemical variations were synthesized and examined. Among these chemical variations, rigid p-phenylene transverse rod and flat-shaped anthraquinone (AQ) mesogenic monomers were specifically incorporated. Thermal and X-ray analysis found a smectic C phase in most of our MCLCEs, which was induced by the strong self-segregation of siloxane spacers, hydrocarbon spacers and mesogenic rods. The smectic C mesophase of the parent LCE was not grossly affected by terphenyl transverse rods. Mechanical studies of MCLCEs indicated the typical three-region stress-strain curve and a polydomain-to-monodomain transition. Strain recovery experiments of MCLCEs showed a significant dependence of strain retentions on the initial strains but not on the chemical variations, such as the crosslinker content and the lateral substituents on mesogenic rods. The MCLCE with p-phenylene transverse rod showed a highly ordered smectic A mesophase at room temperature with high stiffness. Mechanical properties of MCLCEs with AQ monomers exhibit a strong dependence on the specific combination of hydrocarbon spacer and siloxane spacer, which also strongly affect the formation of ð-ð stacking between AQ units. Poisson s ratio measurement over a wide strain range found distinct trends of Poisson s ratio as a function of the crosslinker content as well as terphenyl transverse rod loadings in its parent MCLCEs.

Controlling the micro-structure of organic materials is crucial for a variety of practical applications such as photonics, biomedicine or the rapidly growing field of organic electronics. Recent studies have shown a possibility of tailoring the polymer structure on the nanoscale using supramolecular self-assembly under spatial confinement. Despite extensive studies already performed in this field, many questions remain open. In particular, it will be important to understand how different structure formation processes such as crystallization, LC-phase formation, microphase separation, and others occur under confinement. In the present work, we address the effect of 1D- and 2D-confinement on the structure formation for a variety of systems including segmented poly(ether-ester-amide) (PEEA) copolymers, main-chain liquid-crystalline (LC) polymers belonging to the family of poly(di-n-alkylsiloxane)s and liquid-crystalline/semicrystalline block copolymers formed through complexation of poly (2-vinylpyridine-b-ethylene oxide) (P2VP-PEO) with a wedge-shaped ligand, 4'-(3'',4'',5''-tris(octyloxy) benzamido) propanoic acid. In order to reveal the morphological diversity of the studied systems under confinement, the work was carried out on bulk materials and on thin films employing a battery of experimental methods. The main experimental techniques operational in direct and reciprocal space applied in my work are described in chapter 2. [...]

Aufgrund der zunehmenden technischen Ansprüche der Gesellschaft sind sich aktiv bewegende Polymere in den Mittelpunkt aktueller Forschung gerückt. Diese spielen bei Anwen-dungen im Bereich von künstlichen Muskeln und Implantaten für die minimal invasive Chirurgie eine wichtige Rolle. Vor allem Formänderungs- und Formgedächtnispolymere stehen dabei im wissenschaftlichen Fokus. Während die kontaktlose Deformation einer permanenten Form in eine temporäre metastabile Form, charakteristisch für Formände-rungspolymere ist, kann bei Formgedächtnis-Materialien die temporäre Form, aufgrund der Ausbildung reversibler, temporärer Netzpunkte, fixiert werden. Ein Polymermaterial, das eine Kombination beider Funktionen aufweist würde zu einem Material führen welches kontaktlos in eine temporäre Form deformiert und in dieser fixiert werden kann. Zusätzlich würde aufgrund der kontaktlosen Deformation die Reversibilität dieser Funktion gewähr-leistet sein. Ein solches Material ist bislang noch nicht beschrieben worden. In dieser Arbeit wird untersucht, ob durch die Kopplung zweier separat schaltbarer, be-kannter Funktionen eine neue schaltbare Funktion erzielt werden kann. Daher wurden multi-stimuli sensitive Materialien entwickelt die eine Kopplung des Formänderungs- und des Formgedächtniseffektes aufweisen. Dazu wurden zwei Konzepte entwickelt, die sich hinsichtlich der Reihenfolge der verwendeten Stimuli unterscheiden. Im ersten Konzept wurden flüssigkristalline Elastomere basie-rend auf Azobenzenderivaten aufgebaut und hinsichtlich der Kombination des licht-induzierten Formänderungseffektes mit dem thermisch-induzierten Formgedächtniseffekt untersucht. Diese orientierten Netzwerke weisen oberhalb der Glasübergangstemperatur (Tg) eine kontaktlose Verformung (Biegung) durch Bestrahlung mit UV-Licht des geeigneten Wellenlängenbereichs auf, wodurch eine temporäre Form erhalten wurde. Hierbei spielt der Vernetzungsgrad eine entscheidende Rolle bezüglich der Ausprägung dieser Biegung. Eine fixierte, temporäre Form konnte durch gleichzeitiges Abkühlen des Materials unterhalb von Tg während der Bestrahlung mit UV-Licht erhalten werden. Nach erneutem Aufheizen über Tg konnte die Originalform wiederhergestellt werden. Dieser Vorgang konnte reversibel durchgeführt werden. Damit wurde gezeigt, dass eine neue schaltbare Funktion erzielt wurde, die auf der Kopplung des lichtinduzierten Formänderungs- mit dem thermisch-induzierten Formgedächtniseffekt basiert. Die Abstimmung der einzelnen Funktion wird in diesem Konzept über die Morphologie des Systems gewährleistet. Diese neue Funktion ermöglicht eine kontaktlose Deformation des Materials in eine temporäre Form, welche fixiert werden kann. Im zweiten Konzept wurde eine Kopplung des thermisch induzierten Formänderungs- mit dem licht-induzierten Formgedächtniseffekt angestrebt. Um dies zu realisieren wurden nematisch, flüssigkristalline Hauptkettenelastomere (NMC-LCE) entwickelt, die eine nied-rige Übergangstemperatur der nematischen in die isotrope Phase (TNI), als auch einen aus-geprägten thermisch induzierten Formänderungseffekt aufweisen. Zusätzlich wurde eine photosensitive Schicht aufgebaut, die Cinnamylidenessigsäuregruppen in der Seitenkette eines Polysiloxanrückgrates aufweist. Die Reversibilität der photoinduzierten [2+2]-Cycloaddition konnte für dieses photosensitive Polymer beobachtet werden, wodurch die-ses Polymersystem in der Lage ist reversible temporäre Netzpunkte, aufgrund der Bestrah-lung mit UV-Licht, auszubilden. Die kovalente Anbindung der photosensitiven Schicht an die Oberfläche des flüssigkristallinen Kerns wurde erfolgreich durchgeführt, wodurch ein Multi-Komponenten-System aufgebaut wurde. Die Kombination des thermisch-induzierten Formänderungs- mit dem licht-induzierten Formgedächtniseffektes wurde anhand dieses Systems untersucht. Während die Einzelkomponenten die erforderliche Funktion zeigten, ist hier noch Arbeit in der Abstimmung beider Strukturen zu leisten. Insbesondere die Variation der Schichtdicken beider Komponenten steht im Fokus zukünftiger Arbeiten. In dieser Arbeit wurde durch die Kopplung von zwei separat schaltbaren, bekannten Funktionen eine neue schaltbare Funktion erzielt. Dies setzt voraus, dass die Einzelkomponenten hinsichtlich einer Funktion schaltbar sind und in einem Material integriert werden können. Des Weiteren müssen die beiden Funktionen mit unterschiedlichen Stimuli geschaltet werden. Ein wichtiger Schritt bei der Kopplung der Funktionen, ist die Abstimmung der beiden Komponenten. Dies kann über die Variation der Morphologie oder der Struktur erzielt werden. Anhand der Vielzahl der vorhandenen stimuli-sensitiven Materialien sind verschiedene Kopplungsmöglichkeiten vorhanden. Demnach wird erwartet, dass auf diesem Gebiet weitere neue Funktionen erzielt werden können.
Actively moving polymers are high scientific significance due to their ability to move actively in response to an external stimulus. Most notably shape-change and shape-memory polymers are in the focus of current research. Shape-changing polymers exhibit a non-contact deformation from a permanent into a temporary shape, which is just stable as long the material is exposed to an external stimulus. In contrast shape-memory polymers are capable of a fixed temporary shape due to the formation of additional temporary netpoints, while the deformation is proceed by applying mechanical stress. A polymeric material, which combines both functions would result into a material that possesses the advantages of the shape-change, as well as the shape-memory effect. In this work, the coupling of two known functions is investigated which results into a new switchable function. Therefore, two different concepts were developed requiring different material structures. For the first concept monodomain, smectic liquid-crystalline elastomers (LCE) containing azobenzene moieties were prepared and the coupling of the light-induced shape-change with the thermally-induced shape-memory effect was investigated. These oriented LCE's exhibit a non-contact deformation into a temporary shape, above the glass transition temperature (Tg), due to the irradiation with UV-light. The temporary shape could be fixed by cooling the material below Tg, while the irradiation with light was kept constant. The permanent shape could be recovered by additional heating above Tg. This process could be repeated several times. Therefore, a new switchable function was developed, which based on the coupling of the light-induced shape-change with the thermally induced shape-memory effect. The second concept required a multi-component system and the coupling of the thermally-induced shape-memory withe the light-induced shape-change effect was investigated. The multi component system consists of a LCE-core and a photosensitive layer. Nematic, main-chain elastomers were prepared, which possess of low transition temperatures and high actuation performances. The photosensitive layer consists of cinnamylidene acetic moieties, that were attached to a siloxane backbone, while the photoreversibility of the light-induced [2+2]-cycloaddition was shown. Furthermore, the photosensitive layer was covalently attached to the surface of the LCE-core. While both components showed their functionality, the coupling of the thermally-induced shape-change with the light-induced shape-memory effect was not successful up to now. The Adjustment of both components on each other has to be improved. Mainly the variation of the layer thickness of both structural components should be in the focus of future work.

The thesis work concerns the development of microscopic structures able to perform robotic tasks entirely powered and controlled by light. The two main aspects addressed are the constituent material as well as the technique used for its microstructuring. The materials chosen for the fabrication are Liquid Crystalline Elastomers (LCEs), a type of shape-changing polymers that have attracted scientists and engineers for their ability to translate small molecular movement, triggered by an external stimulus, into large mechanical motion. Regarding the fabrication of microstructures, we chose the Direct Laser Writing (DLW), a technique based on a point-by-point polymerization induced by two photon absorption in the focus of a laser beam, where a tiny voxel is polymerized with high precision. Direct Laser Writing allows a rapid, cheap and flexible fabrication of microscale objects with nanoscale precision. The successful fabrication of LCE microstructures able to deform under light irradiation is demonstrated open to a new technology for the realization of complex microrobots.

Nanotechnology plays a central role in ‘tailoring’ materials’ properties and thus improving its performances for a wide range of applications. Coupling nature nano-objects with nanotechnology results in materials with enhanced functionalities. The main objective of this master thesis was the synthesis of nanocrystalline cellulose (NCCs) and its further incorporation in a cellulosic matrix, in order to produce a stimuli-responsive material to moisture. The induced behaviour (bending/unbending) of the samples was deeply investigated, in order to determine relationships between structure/properties. Using microcrystalline cellulose as a starting material, acid hydrolysis was performed and the NCC was obtained. Anisotropic aqueous solutions of HPC and NCC were prepared and films with thicknesses ranging from 22μm to 61μm were achieved, by using a shear casting technique. Microscopic and spectroscopic techniques as well as mechanical and rheological essays were used to characterize the transparent and flexible films produced. Upon the application of a stimulus (moisture), the bending/unbending response times were measured. The use of NCC allowed obtaining films with response times in the order of 6 seconds for the bending and 5 seconds for the unbending, improving the results previously reported. These promising results open new horizons for building up improved soft steam engines.

Smart soft materials possess an unmatched potential in biomedical applications. Among them, liquid crystalline elastomers (LCEs) exhibit various properties exploited in the fabrication of microrobots and responsive coatings, and, very recently, also in the design of biomedical implants and devices. LCEs are shape-changing materials able to modify their structure upon stimulation, generating tension during this process. Biocompatibility and cell-instructiveness have been demonstrated for different classes of LCEs, whose mechanical properties and response time can be easily tuned. The research presented in this Thesis follows two applications of LCEs in the biomedical field. In the first part of the study, LCEs were investigated as artificial muscles. Starting from the demonstration of the ability of films obtained from a light-responsive LCE mixture in assisting cardiac contraction, its composition was tuned to improve its performance, and completely characterized in terms of efficiency, level of tension developed upon stimulation and kinetics of force development. The aims of the work were to find the correct light stimulation pattern and azobenzene-based dye to enhance its capabilities in muscle assistance and to miniaturize an implantable LCE-miniLED device. In the second part of the research, the ability of different supports to direct cell culturing was approached. The effect of different surface patterning methods on two different materials on cell adhesion and growth was evaluated. In the first study, the ability of linear motifs in directing cell alignment and growth of cardiomyocytes derived from human induced pluripotent stem cells, on hydrogels made of commercially available polymers, was pinpointed. Substrate rigidity was modulated to assess the relation between this parameter and cell functionality. The focus of the second study was the development of reconfigurable coatings based on light-responsive LCEs. Surfaces were patterned with fingerprint-like structures, which arose from self-assembly of a mixture of mesogenic monomers doped with a chiral crosslinker. The surfaces possessed hills and valleys with different molecular alignment, that underwent topography inversion upon irradiation. Different types of coatings were prepared, tuning pattern spacing, roughness and actuation level. The biocompatibility of the materials was studied in view of their use as active cell culture scaffolds capable of live stimulation of cultured cells.

碩士
中原大學
化學工程研究所
86
A series of semi-aromatic thermotropic liquid crystalline poly(amide-ester) and polyester elastomers were prepared by direct polycondensation from various aromatic diacid (e.g. TPA, DBAC or PEG4) with various aromatic diamine (e.g. ODA, BDAM or NDAM), various diols (e.g. PhHQ, BPO, MHQ, BP, PEG-200, PEG-600, PEG-1000 or isosorbide), respectively, in the presence of diphenyl chlorophosphate(DPCP), LiCl and pyridine. In order to investigate the relationship between the structures and the LC properties of the synthesized poly(amide-ester) and polyester elastomers, all of the synthesized polymers were examined by DSC, polarized microscope with a heating stage, WAXD, TGA and DMA. For preparing LC poly(amide-ester)s and polyester elastomers with long soft segments, it was found that aspect ratio of the hard segments should be extented. However, on the other hand, the transition temperatures of the hard segment were suppose to be reduced to show LC properties, because the thermostabilities of the soft segments were relatively poor. Synthesizing alternating LC elastomers could lower the transation temperation temperature effectively. In this study, we also attempted to prepare novel cholesteric LC elastomers by introducing the amount of isosorbide, as a chiral diol monomer, which is lower than 25 mole ﹪. In addition, the synthesized poly(amide-ester) and polyester elastomers possessed excellent thermostabilties (the 5 wt ﹪ loss temperature is higher than 400 ℃).

碩士
中原大學
化學工程學系
87
In the first part of this study, a diamine monomer, (2,2’-diacryloyl-4,4’-diaminobiphenyl), containing crosslinkable and mesogen functional group was synthesized using 2-2’-diacryloyl-4,4’-dinitrobiphenyl as the starting material by various kind of reduction methods. In order to investigate the influence of the reduction methods on the yield and structure of diamine monomer, the reduction products were analyzed and identified by FTIR, NMR and elemetal analysis. The nitro functional group reduced into amine group by using calcium chloride mixing with iron powder and hydrochloric acid containing iron powder as the reduction agents would not reduce carbon-carbon double bond simultaneously. However, by using others reduction agents, the carbon-carbon double would be reduced with nitro group at the same time. In the second part, the diamine monomer synthesized by using hydrochloric acid and iron powder as the reduction agent reacted with various diacids, diols, and aromatic acids, which contain hydroxy group in one end and carboxyl group in the other end, were polymerized by using direct polycodensation to obtain a series of side chain crosslinkable aromatic poly(amide-ester)s. In order to investigate the effect of the kind of monomer and its structure on the thermal properties of obtained polymer, the obtained polymers were measured by DSC, TGA, and polarized microscope with a heating stage. The polymer synthesized by introducing of PEG4 diacid monomer which containing flexible spacer possessed lower melting point and higher inherent viscosity than those of polymers synthesized from TPA, IPA, and NAAC diacid monomers. Furthermore, except polymer 3a, all of the polymers did not exhibt thermotropic liquid crystalline properties.

A surface is the interface between a system and the environment that surround it. It can be of many different nature, from cells (as skin) to polymers and it usually play a critical role both in many biological functions and in different technological applications. In nature, several examples demonstrate how a particular surface structuration (or chemical composition) results essential for the interactions with the environment, allowing for example for self-cleaning or water harvesting. Technological applications extensively took inspiration by nature in order to reproduce or even improve well-known and consolidated functionalities. Among them, special attention was deserved to the development of surfaces with controllable wettability, to be applied in different research fields, and to improve biocompatible surfaces for biological applications. This thesis focuses on the preparation and characterization of different microstructured and stimuli-responsive surfaces. Different synthetic approaches and structuration strategies were explored to tailor the chemical-physical properties of the substrates. Such results were developed towards multiple applications in very different films: form the surface wettability modification to the cell scaffold development. The former was investigated to prepare surfaces with controlled wettability from superhydrophobic to superhydrophilic. The latter to improve the maturation of cardiomyocytes on hydrogel-based micro-patterned surfaces. We exploited different surface modifications from covalent modification of glassy or polymeric surface, up to physical micro-structuration realized by lithographic techniques and photopolymerization reactions. The materials chosen for the fabrication of micro-structured surfaces for self-cleaning applications were Liquid Crystalline Elastomers (LCEs), smart polymers that have attracted scientists’ attention for their ability to reversibly deform under specific external stimulus. On the other hand, we chose hydrogel-based surfaces to improve cellular growth and, in particular, poly(ethylene glycol) (PEG) was used in this thesis for its high biocompatibility and tuneable mechanical properties. In both cases, photopolymerization of different acrylate based monomers was employed in combination with soft lithography to shape the material surface with a micro-structured fashion. Towards self-cleaning applications, our main goal was the realization of a surface whose wettability could be dynamically controlled by a remote stimulus, controlling both the morphology and/or the chemical composition of the surface. We selected light as a trigger to change the surface properties, because it allows rapid, local, and wireless control on a specific area opening to the realization of microfluidic devices. Several surface geometries have been tested with two different LC materials, demonstrating how to tune the water contact angle from 80° to 130° only by playing on the material topography, while surface adhesion can be modified by silanization procedure to achieve water repellent surfaces. To obtain a dynamic control on the wettability, a light controlled reshaping of the microstructures was tested but the resulting wettability variation resulted very limited. New procedures to obtain more homogeneous liquid crystalline alignment or the use of more responsive materials are under evaluation to enhance the dynamic control on the surfaces. Regarding the second application targeted, we focussed on the realization of micro-structured surfaces able to drive the proliferation and the differentiation of cells for tissue engineering. Soft-lithography was explored to realize biomimetic substrates able to drive effective maturation of the stem cells that closely resemble adult cells and, in particular, micropatterned PEG hydrogel were used as substrate for human induced pluripotent stem cells-derived cardiomyocytes (hiPSC-CMs) culture. Our scaffolds have been demonstrated able to drive the right maturation, in terms of cellular shape and functionalities, of these cells improving their functionalities with respect to cells cultured on other commercial substrates. Action potential (AP) and calcium transients (CaT) characterizations allowed to demonstrate a cellular like-adult behaviour after 60 days of culture, improving the cellular functional maturation until 90 days. Also the morphological characterization, monitored with the sarcomere length of the cells, confirmed the previous functional analysis. Thanks to an ongoing collaboration, these substrates are currently under evaluation for the modelling of the Duchenne dystrophy by group of Dr. Cecilia Ferrantini and Prof. Corrado Poggesi at the Department of Experimental and Clinical Medicine (division of physiology) of the University of Florence . In order to improve the shape changing behaviour of our LCEs, and thus to overcome major limitations highlighted during the development of surfaces with controllable wettability, but also to move towards responsive cell scaffolds (with the aim to explore the effect of a stimulated scaffold on hiPSC-CMs maturation) also a new synthetic approach was explored. Thiol-yne click reaction was studied as a non-conventional methodology for the fabrication of LCEs characterized by mixed main-chain/side-chain architecture. This molecular arrangement was demonstrated able to support bigger deformations under thermal stimuli with respect to standard polyacrylate LCEs A small library of thiols and alkynes was synthesized and used to fabricate polymeric actuators with different actuation temperatures. Differential Scanning Calorimetry analysis revealed as changing mesogenic cores inside the main-chain is an efficient strategy to modulate the transition temperatures of the final materials (around 150 °C for core containing three aromatic rings and 80°C for those containing two rings). On the other hand, polymers containing three-aromatic ring cores showed bigger extent in deformation (until 41% of the initial length) with respect to polymer containing two aromatic ring cores (16%). Very interestingly, the different temperature range for the thermal contraction of the different materials could be exploited to assemble actuators composed by parts that respond in a selective way in different environment (e.g. at the variation in temperature). Insertion of azobenzene dyes also in these polymers and their use to prepare micropatterned substrate are under evaluation in our laboratories.

The results of this Ph.D. thesis demonstrate the tunability of photonic platforms by introducing stimuli responsive polymers as constituents of the photonic structure itself or as thermally driven mechanical actuators. In particular, liquid crystalline networks (LCNs) were patterned by lithographic techniques, such as direct laser writing (DLW) and UV polymerization to develop and fabricate tunable photonic crystals for different applications, from tunable telecom filters to tunable structural colors and intelligent sensors, featuring good optical properties that can be controlled and modulated by multiple tuning mechanisms (e.g. temperature and light). In order to optimize the structure design and the tunability of LCN photonic devices, the refractive index and the tunable optical anisotropy (determined by the chemical composition of the material, the fabrication parameters, and the molecular ordering) have been precisely characterized. As first, it has been demonstrated, using a refractometer method, that optical properties of these new photonic materials can be tuned by adjusting mesogenic concentration both in LCN macro- and micro-structures. The tailored chemical formulation allows not only the determination of the shape changing properties of LCNs but also the modulation of the refractive indices and the optical anisotropy of liquid crystalline mixtures, which can be tuned at different temperatures or alternatively by laser light irradiation. Aiming to increase the fabricated structure resolution, a second result demonstrated how refined fabrication resolutions, never yet reached for liquid crystalline networks, can be achieved at low polymerization temperatures (5°C-10°C) using opportune writing parameters. The resulting 3D polymerizable unit, now comparable with the typical voxel of commercial resists, enlarges the application field of photo-responsive elastic materials without degradation of the patterned structure rigidity. Indeed, a spheroidal voxel would be the best polymerization unit to fabricate three-dimensional structures, especially in 3D photonic structures as woodpile photonic crystals for which isotropic voxel dimensions are needed. The best fabrication parameters using the DLW lithographic technique at controlled temperature enabled the fabrication of the first 3D woodpile photonic crystal made by LCN, having a geometric resolution and a light transmission attenuation at the stop band comparable with photonic crystal fabricated with commercial resists. This demonstrates the effectiveness of our previous study. Such photonic crystal has been characterized using temperature as an external stimulus to tune its optical properties in order to demonstrate its potential as a tunable filter at telecom wavelength. Finally, the first proof-of-concept of a smart millimetric optical sensor was developed during a six-month period in collaboration with Prof. Li and Prof. Keller group in Paris, at ChimieParis Tech. A temperature responsive actuator has been combined with the back side of the Morpho Menelaus wing, owing an optimized structural coloration due to its natural photonic crystal structure. Two different strategies have been proposed to control the visual sensor: a macroscopic deformation of the combined system induces an iridescence variation, whereas a nanoscale contraction generates a color shift through the lamellae interspacing variation, parameter that determines the structural coloration. In conclusion, this thesis focused on the material characterization of smart polymers and their nanopatterning for tunable photonic shows as the employ of smart LCNs can be extended from mechanical actuators and microrobotics to micrometric photonic structures for new multifunctional devices.