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Magnetostrictive materials are essential components in sensors, actuators, and energy‐storage devices due to their ability to convert mechanical stress into changes in magnetic properties and vice‐versa. However, their operation typically requires physical contact to apply stress or relies on magnetic field sources to control magnetic properties. This poses significant limitations to devices miniaturization and their integration into contactless technologies. This work reports on an approach that overcomes these limitations by using light to transfer mechanical stress to a magnetostrictive device, thereby achieving non‐contact and reversible opto‐mechanical control of its magnetic and electrical properties. The proposed solution combines a magnetostrictive Fe70Ga30 thin film with a photo‐responsive Liquid Crystalline Network (LCN). Magnetic properties are modulated by changing the light wavelength and illumination time. Remarkably, the stable shape change of the LCN induced by ultraviolet (UV) light leads to the retention of magnetic properties even after the light is switched off, resulting in a magnetic memory effect with an energy consumption advantage over the use of conventional magnetic field applicators. The memory effect is erased by visible light, which releases the mechanical stress in the photoresponsive layer. Therefore, this new composite material creates a fully reconfigurable magnetic system controlled by light. [ABSTRACT FROM AUTHOR]

A liquid crystalline elastomer (LCE) network consisting of dynamic covalent bonds (DCBs) is referred as a LCE vitrimer. The mesogen alignment and the network topology can be reprogrammed locally in the LCE vitrimer by activating the bond exchange reactions using an external stimulus. After removal of the external stress, a new network is formed and the reprogrammed shape can be fixed, leading to a different set of the physical properties of the LCE vitrimers. Herein, this type of emerging materials is reviewed by a brief introduction of the fundamentals of LCEs, followed by discussions of various DCBs and the design principles for LCE vitrimers. After a presentation of different strategies to improve the stability and reprogrammability of the registered mesogen alignment, approaches to prepare LCE vitrimers with complex shapes and their actuations are discussed. Potential applications such as self‐healing and recycling, mechanochromic effects, and post‐functionalization of nanopores are also reviewed, followed by the conclusion of the remaining challenges and opportunities. [ABSTRACT FROM AUTHOR]

Photonic crystals owe their multitude of optical properties to the way their structure creates interference effects. It is therefore possible to influence the photonic response by acting on their physical structure. In this article, tunable photonic crystals made by elastic polymers that respond to their environment are explored, in particular with a physical deformation under temperature variation. This creates a feedback process in which the photonic response depends on its physical structure, which itself is influenced by the environmental changes. By using a multi‐photon polymerization process specifically optimized for soft responsive polymers such as Liquid Crystalline Networks, highly resolved, reproducible, and mechanically self‐standing photonic crystals are fabricated. The physical structure of the 3D woodpile can be tuned by an external temperature variation creating a reversible spectral tuning of 50 nm in the telecom wavelength range. By comparing these results with finite element calculations and temperature induced shape‐change, it is confirmed that the observed tuning is due to an elastic deformation of the structure. The achieved nanometric patterning of tunable anisotropic photonic materials will further foster the development of reconfigurable photonic crystals with point defects acting as tunable resonant cavities and, more in general, of 4D nanostructures. [ABSTRACT FROM AUTHOR]

Phase behavior modulation of liquid crystalline molecules can be addressed by structural modification at molecular level. Starting from a rigid rod‐like core reduction of the symmetry or increase of the steric hindrance by different substituents generally reduces the clearing temperature. Similar approaches can be explored to modulate the properties of liquid crystalline networks (LCNs)—shape‐changing materials employed as actuators in many fields. Depending on the application, the polymer properties have to be adjusted in terms of force developed under stimuli, kinetics of actuation, elasticity, and resistance to specific loads. In this work, the crosslinker modification at molecular level is explored towards the optimization of LCN properties as light‐responsive artificial muscles. The synthesis and characterization of photopolymerizable crosslinkers, bearing different lateral groups on the aromatic core is reported. Such molecules are able to strongly modulate the material mechanical properties, such as kinetics and maximum tension under light actuation, opening up to interesting materials for biomedical applications. [ABSTRACT FROM AUTHOR]

Liquid crystalline polymers (LCPs), especially liquid crystalline elastomers (LCEs) can generate ultrahigh shape change amplitude but has lower mechanical strength. Although some attempts have been tried to improve the mechanical performance of LCE, there are still limitations including complicated fabrication and high actuation temperature. Here, a versatile method is reported to fabricate light‐driven actuator by covalently cross‐linking polyurethane (PU) into LCP networks (PULCN). This new scheme is distinct from the previous interpenetrating network strategy, the hydrogen bonds and covalent bonds are used in this study to improve the miscibility of non‐liquid‐crystalline PU and LCP materials and enhance the stability of the composite system. This material not only possesses the shape memory properties of PU but shows shape‐changing behavior of LCPs. With a shrinkage ratio of 20% at the phase transition temperature, the prepared materials reached a maximum mechanical strength of 20 MPa, higher than conventional LCP. Meanwhile, the resulting film shows diverse and programmable initial shapes by constructing crosslinking density gradient across the thickness of the film. By integration of PULCN with near‐infrared light‐responsive polydopamine, local and sequential light control is achieved. This study may provide a new route for the fabrication of programmable and mechanically robust light‐driven soft actuator. [ABSTRACT FROM AUTHOR]

Mimicking compositions and structures of extracellular matrix is widely studied to create in vitro tumor models, to deepen the understanding of the pathogenesis of the different types of cancer, and to identify new therapies. On the other hand, the use of synthetic materials to modulate cancer cell biology and, possibly, to reduce the malignancy of cancer cells through their exploitation is far less explored. Here, the study evaluates the effects of Liquid Crystalline Networks (LCNs) based scaffolds on the growth of A375 metastatic melanoma cells. Interestingly, cells grown on such materials show reduced cell proliferation and colony-forming capacity with respect to those cultivated on standard plates. These effects are associated with a higher percentage of senescent cells and a shift to a more epithelial phenotype, pointing to the occurrence of a mesenchymal to epithelial transition. All these biological outcomes are affected by the amount of crosslinker in the material and have been induced only thanks to the interactions with the polymeric substrate without the need of further chemical (e.g., specific growth factor) or physical (e.g., irradiation) stimuli, opening to the possible development of anti-cancer coatings., (© 2025 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

With the growing demand for soft robots capable of various degrees of locomotion based on reversibly actuating liquid crystalline networks (LCNs), the fabrication of complex 3D architectures from 2D LCN films via shape reconfiguration and/or assembly techniques are studied recently. However, once a system is formed and fixed into a specific 3D structure, only certain movements can be implemented using the fixed structure, and disassembly into the original 2D films is challenging. Therefore, studies to overcome this irreversible fabrication process become increasingly important. Herein, an effective and simple preparation of static and dynamic covalent dual‐cross‐linked, photo‐controllable LCN (pc‐LCN) films as building blocks for lego‐like, monolithically assembled 3D soft transformable robots is presented. By tailoring the static and dynamic covalent linkages in the networks, pc‐LCN films can be readily reconfigured and assembled into complex 3D structures under ultraviolet (UV) irradiation. Such monoliths can also be disassembled into their constituent building block films and reassembled into different architectures under the same UV stimulation. Moreover, by adopting selective visible‐light‐responsive dopant dyes to actuate pc‐LCN building blocks, 3D soft transformable robots with versatile motion capabilities, including rolling, gripping, and cargo transport in multiple directions, are demonstrated. [ABSTRACT FROM AUTHOR]

With the growing demand for soft robots capable of various degrees of locomotion based on reversibly actuating liquid crystalline networks (LCNs), the fabrication of complex 3D architectures from 2D LCN films via shape reconfiguration and/or assembly techniques are studied recently. However, once a system is formed and fixed into a specific 3D structure, only certain movements can be implemented using the fixed structure, and disassembly into the original 2D films is challenging. Therefore, studies to overcome this irreversible fabrication process become increasingly important. Herein, an effective and simple preparation of static and dynamic covalent dual‐cross‐linked, photo‐controllable LCN (pc‐LCN) films as building blocks for lego‐like, monolithically assembled 3D soft transformable robots is presented. By tailoring the static and dynamic covalent linkages in the networks, pc‐LCN films can be readily reconfigured and assembled into complex 3D structures under ultraviolet (UV) irradiation. Such monoliths can also be disassembled into their constituent building block films and reassembled into different architectures under the same UV stimulation. Moreover, by adopting selective visible‐light‐responsive dopant dyes to actuate pc‐LCN building blocks, 3D soft transformable robots with versatile motion capabilities, including rolling, gripping, and cargo transport in multiple directions, are demonstrated.

Enhancing the resolution of 3D patterning techniques in functional soft polymers enlarges the application areas of responsive shape‐changing materials, for tunable nanophotonics and nanorobotics. Thanks to the recent advances of polymer science, the palette of available materials for nanomanufacturing is becoming wider and wider—although the comprehension of their polymerization process by two‐photon polymerization is still incomplete. In this work, both shrinking of the minimal polymerizable unit and a significant improvement of the mechanical stability of microstructured soft polymers, in particular of liquid crystalline networks, are demonstrated. To this aim, temperature control enhances the resolution and reduces the swelling of the polymerized structures, thus avoiding deviations of the final structure from the intended design. This fine control on the nanoscale features enables the use of soft responsive materials not only for bulky microelements, but also for high‐resolution structures with more complex design. [ABSTRACT FROM AUTHOR]

Imitating the structures and behaviors of natural creatures is of great significance to scientists to explore novel materials for practical applications. However, the design and fabrication of biomimetic devices with complex and outstanding performances is still on the way. A bilayer film composed of liquid crystalline networks (LCN) film and hydrochromic aggregation‐induced‐emission molecule‐doped hydrophilic layer is prepared. Under different relative humidity, the composite film can deform and change fluorescence color simultaneously. The influence of the content of the hydrophilic matrix on the fluorescent property and humidity‐responsive behaviors of the bilayer film is investigated. Thanks to the mechanical anisotropy provided by uniform‐aligned LCN film, different modes of deformation of the bilayer film are achievable, like bending, curling, and twisting. More importantly, due to the independence of the LCN film and the non‐mesogenic molecules brought by this bimorph strategy, complex alignment of the LCN film and modification by immiscible molecules are realized in a single LCN actuator. Based on the functional composite film, artificial flowers showing synergistic blooming and shape‐changing is prepared. By regulating the molecular alignment of the LC mesogens of the LCN film, the artificial flowers can imitate various blooming behaviors of natural flowers like confederate jasmine and jade lotus. [ABSTRACT FROM AUTHOR]

Constructing soft robotics with safe human-machine interactions requires low-modulus, high-power-density artificial muscles that are sensitive to gentle stimuli. In addition, the ability to resist crack propagation during long-term actuation cycles is essential for a long service life. Herein, a material design is proposed to combine all these desirable attributes in a single artificial muscle platform. The design involves the molecular engineering of a liquid crystalline network with crystallizable segments and an ethylene glycol flexible spacer. A high degree of crystallinity can be afforded by utilizing aza-Michael chemistry to produce a low covalent crosslinking density, resulting in crack-insensitivity with a high fracture energy of 33 720 J m -2 and a high fatigue threshold of 2250 J m -2 . Such crack-resistant artificial muscle with tissue-matched modulus of 0.7 MPa can generate a high power density of 450 W kg -1 at a low temperature of 40 °C. Notably, because of the presence of crystalline domains in the actuated state, no crack propagation is observed after 500 heating-cooling actuation cycles under a static load of 220 kPa. This study points to a pathway for the creation of artificial muscles merging seemingly disparate, but desirable properties, broadening their application potential in smart devices., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

Design and fabrication of photomechanical soft actuators has attracted intense scientific interest because of their potential in the manufacture of untethered intelligent soft robots and advanced functional devices. Trifunctional and monofunctional polymerizable molecular motors are judiciously designed and synthesized. Novel light‐driven liquid crystalline networks (LCN) are prepared by crosslinking overcrowded‐alkene‐based molecular motors with different degrees of freedom into the anisotropic LCN. The photoisomerization and thermal helix inversion of light‐driven molecular motors are reversible when only the upper part of the molecular motor is linked to the network, endowing the LCN film with remarkable photoactive performance. However, photochemical geometric change of the light‐driven molecular motor does not work after crosslinking both the upper and lower part of the motor by polymer chains. Interestingly, it is found that the fastened motor can transfer the light energy into localized heat instead of performing photoisomerization. The light‐driven molecular‐motor‐based LCN soft actuators are demonstrated to function as a grasping hand, where the continuous motions of grasping, moving, lifting, and releasing an object are successfully achieved. This work may provide inspiration to the preparation of next‐generation photoactive advanced functional materials toward their wide applications in the areas of photonics, optoelectronics, soft robotics, and beyond. [ABSTRACT FROM AUTHOR]

Two-photon direct laser writing enables the fabrication of shape-changing microstructures that can be exploited in stimuli responsive micro-robotics and photonics. The use of Liquid Crystalline Networks (LCN) allows to realize 3D micrometric objects that can contract along a specific direction in response to stimuli, such as temperature or light. In this paper, the fabrication of free-standing LCN microstructures is demonstrated as graphical units of a smart tag for simple physical and optical encryption. Using an array of identical pixels, information can be hidden to the observer and revealed only upon application of a specific stimulus. The reading mechanism is based on the shape-change of each pixel under stimuli and their color that combine together in a two-level encryption label. Once the stimulus is removed, the pixels recover their original shape and the message remains completely hidden. Therefore, an opto-mechanical equivalent of an "invisible ink" is realized. This new concept paves the way for introducing enhanced functionalities in smart micro-systems within a single lithography step, spanning from storage devices with physical encryption to complex motion actuators., (© 2023 The Authors. Small published by Wiley‐VCH GmbH.)

Abstract: Materials whose optical response is determined by their structure are of much interest both for their fundamental properties and applications. Examples range from simple gratings to photonic crystals. Obtaining control over the optical properties is of crucial importance in this context, and it is often attempted by electro‐optical effect or by using magnetic fields. In this paper, the use of light is introduced to switch and tune the optical response of a structured material, exploiting a physical deformation induced by light itself. In this new strategy, light drives an elastic reshaping, which leads hence to a change in the optical response. This is made possible by using liquid crystalline networks structured by direct laser writing. As a proof of concept, a grating structure with sub‐millisecond time response is demonstrated for optical beam steering, exploiting an optically induced reversible shape change. Experimental observations are combined with finite‐element modeling in order to understand the actuation process dynamics, and to obtain information on how to tune the time and the power response of this technology. This optical beam steerer opens up full optical control of light in a broad range of structured optical materials. [ABSTRACT FROM AUTHOR]

Tunable metal-insulator-metal (MIM) Fabry-Pérot (FP) cavities that can dynamically control light enable novel sensing, imaging and display applications. However, the realization of dynamic cavities incorporating stimuli-responsive materials poses a significant engineering challenge. Current approaches rely on refractive index modulation and suffer from low dynamic tunability, high losses, and limited spectral ranges, and require liquid and hazardous materials for operation. To overcome these challenges, a new tuning mechanism employing reversible mechanical adaptations of a polymer network is proposed, and dynamic tuning of optical resonances is demonstrated. Solid-state temperature-responsive optical coatings are developed by preparing a monodomain nematic liquid crystalline network (LCN) and are incorporated between metallic mirrors to form active optical microcavities. LCN microcavities offer large, reversible and highly linear spectral tuning of FP resonances reaching wavelength-shifts up to 40 nm via thermomechanical actuation while featuring outstanding repeatability and precision over more than 100 heating-cooling cycles. This degree of tunability allows for reversible switching between the reflective and the absorbing states of the device over the entire visible and near-infrared spectral regions, reaching large changes in reflectance with modulation efficiency ΔR = 79%., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

Liquid crystalline networks (LCNs) are described in which there is anelasticity in strain recovery response (under zero load) after uniaxial tensile loading. This strain retention is shown as a function of time after release of load and is further characterized by thermal, X-ray, and stress/strain experiments. It was found that, at temperatures in the smectic phase far below the isotropization temperature, this LCN film retains significant levels of strain when in the monodomain state. On free recovery (zero load) of the LCN film there is a rapid elastic response followed by a slow anelastic response for those films that had undergone a polydomain-to-monodomain transition during the initial imposed strain regimen. It is postulated that the mechanism leading to the strain retention involves nanosegregation-driven pinning of unfolded hairpins in shallow energy wells and that this effect is responsible for the thermally activated recovery of strain (shape memory) at elevated temperatures. [ABSTRACT FROM AUTHOR]

Abstract: Microcapsules based on a new liquid crystalline lightly cross-linked polyamide, in which the state of order can be triggered by means of external stimuli, such as temperature and light, were prepared by interfacial polymerization. This polyamide exhibited a nematic phase up to 166°C and it started to decompose at 340°C; morphological variations of the film were observed by Scanning Electron Microscopy in correspondence to the clearing temperature; moreover, by continuous irradiation with UV light at room temperature, the polymer underwent E–Z photoisomerization. The prepared microcapsules contained either toluene, or concentrated solutions of naphthalene or β-carotene, as the core; in all cases, their outer surface appeared smooth and dense, while heterogeneities could be seen on the inner face. Capsule diameter lay in the range 30–120μm, depending on the encapsulated material, with quite narrow size distributions. To the authors’ knowledge, this is the first example of microcapsules whose shell is completely constituted by a liquid crystalline lightly cross-linked polymer. Release experiments of β-carotene were performed in water and in tetrahydrofuran. β-Carotene release in water at 20°C was strongly influenced by UV irradiation: in the absence of irradiation, it was practically negligible while, when microcapsules were submitted to continuous irradiation with UV light, β-carotene was quickly released and reached 100% release after 5min. Preliminary experiments concerning the effect of temperature and of a swelling solvent, such as THF, on release, were also performed. [Copyright &y& Elsevier]

The ability to obtain 3D polymeric objects by a 2D-to-3D shape-shifting method is very appealing for polymer integration with different materials, from metals in electronic devices to cells in biological studies. Such functional reshaping can be achieved through self-folding driven by a strain pattern designed into the molecular network. Among polymeric materials, liquid crystalline networks (LCNs) present an anisotropic molecular structure that can be exploited to tailor internal strain, resulting in a natural non-planar geometry when prepared in the form of flat films. In this article, we analyze the influence of different molecular parameters of the monomers on the spontaneous shape of the polymeric films and their deformation under different stimuli, such as heating or light irradiation. Modifying the alkilic chains of the crosslinkers is a simple and highly effective way to increase the temperature sensitivity of the final actuator, while modifying ester orientation on the aromatic core interestingly acts on the bending direction. Combining such effects, we have demonstrated that LCN stripes made of different monomeric mixtures originate complex non-symmetric deformation under light activation, thus opening up new applications in photonic and robotics. [ABSTRACT FROM AUTHOR]

Polymer photonics explores manufacturing of polymeric materials in order to create devices for light manipulation at the nanoscale. Available lithographic techniques give access to a truly 3D shaping, which can replicate computer‐aided designs by several methods. Among them, direct laser writing enables nanoscale precision fabrication. This platform allows integration of advanced materials for reconfigurable elements, whose shape and refractive index can be precisely controlled by external stimuli. This Progress Report collects the recent advances in the field of light‐tunable photonics, where polymers are used not only as passive elements for guiding and manipulating light but also to control the optical properties of the devices themselves. This creates dynamic structures with multifunctional performance. Starting from a brief description of light‐responsive materials patterned by direct laser writing (focusing on liquid crystalline networks), examples of integration of photonic materials on different platforms are shown—from simple photonic devices (as lenses or diffraction gratings) to their integration in photonic circuits (as active whispering gallery mode resonator coupled to waveguide). As most of the active materials are demonstrated to be biocompatible, implantable photonic platforms can be foreseen for biomedical applications. [ABSTRACT FROM AUTHOR]

In the last several years, multiple‐shape memory liquid crystalline networks (LCNs) have received more and more attention due to the basic theoretical research on them and their wide potential applications. In this article, a novel main‐chain/side‐chain liquid crystalline monomer and its corresponding polymer networks based on the thiol‐ene click reaction are reported. Properties of the synthesized liquid crystalline monomer are well studied with nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC), and polarized optical microscopy (POM). The as‐prepared free‐standing LCN films are investigated well by FTIR, DSC, POM, and X‐ray diffraction (XRD), which show them having good liquid crystalline properties. Tensile test and dynamical mechanical analysis (DMA) results indicate the LCN films have excellent thermal mechanical properties. By adjusting the crosslinking densities, LCN films exhibit two thermal transition temperatures (Tg and TNI) that can be utilized to trigger the triple‐shape memory behaviors. The cyclic thermal mechanical analysis conducted by DMA reveals that LCN films exhibit good triple‐shape memory properties with high‐shape fixity ratio (Rf (S1→S2) is 99.2% and Rf (S2→S3) is 99.3%) and shape recovery ratio (Rr (S3→S2) is 92.4% and Rr (S2→S1) is 98.5%). [ABSTRACT FROM AUTHOR]

The communication reports the use of liquid crystalline networks (LCNs) for engineering tissue cultures with human cells. Their ability as cell scaffolds for different cell lines is demonstrated. Preliminary assessments of the material biocompatibility are performed on human dermal fibroblasts and murine muscle cells (C2C12), demonstrating that coatings or other treatments are not needed to use the acrylate-based materials as support. Moreover, it is found that adherent C2C12 cells undergo differentiation, forming multinucleated myotubes, which show the typical elongated shape, and contain bundles of stress fibers. Once biocompatibility is demonstrated, the same LCN films are used as a substrate for culturing human induced pluripotent stem cell-derived cardiomyocites (hiPSC-CMs) proving that LCNs are capable to develop adult-like dimensions and a more mature cell function in a short period of culture in respect to standard supports. The demonstrated biocompatibility together with the extraordinary features of LCNs opens to preparation of complex cell scaffolds, both patterned and stimulated, for dynamic cell culturing. The ability of these materials to improve cell maturation and differentiation will be developed toward engineered heart and skeletal muscular tissues exploring regenerative medicine toward bioartificial muscles for injured sites replacement., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, the decisive role of rigidity, orientation, and order in the smectic liquid crystalline network on the anisotropic proton and adsorbent properties is reported. The rigidity in the hydrogen-bonded polymer network has been altered by changing the cross-link density, the order by using different mesophases (smectic, nematic, and isotropic phases), whereas the orientation of the mesogens was controlled by alignment layers. Adding more cross-linkers improved the integrity of the polymer films. For the proton conduction, an optimum was found in the amount of cross-linker and the smectic organization results in the highest anhydrous proton conduction. The polymer films show anisotropic proton conductivity with a 54 times higher conductivity in the direction perpendicular to the molecular director. After a base treatment of the smectic liquid crystalline network, a nanoporous polymer film is obtained that also shows anisotropic adsorption of dye molecules and again straight smectic pores are favored over disordered pores in nematic and isotropic networks. The highly cross-linked films show size-selective adsorption of dyes. Low cross-linked materials do not show this difference due to swelling, which decreases the order and creates openings in the two-dimensional polymer layers. The latter is, however, beneficial for fast adsorption kinetics.

Functional polymers are intelligent materials that can respond to a variety of external stimuli. However, these materials have not yet found widespread real world applications because of the difficulties in fabrication and the limited number of functional building blocks that can be incorporated into a material. Here, we demonstrate a simple route to incorporate three functional building blocks (azobenzene chromophores, liquid crystals, and dynamic covalent bonds) into an epoxy-based liquid crystalline network (LCN), in which an azobenzene-based epoxy monomer is polymerized with an aliphatic dicarboxylic acid to create exchangeable ester bonds that can be thermally activated. All three functional building blocks exhibited good compatibility, and the resulting materials exhibits various photomechanical, shape memory, and self-healing properties because of the azobenzene molecules, liquid crystals, and dynamic ester bonds, respectively.