Reprogrammable elastomers with dynamic covalent bonds are of paramount significance for emerging applications such as adaptive optics and soft robotics. In their Research Article (e202116219), Ling Wang, Wei Feng, and co‐workers describe mechanochromic, shape‐programmable, and self‐healable cholesteric liquid crystal elastomers obtained by introducing dynamic covalent boronic ester bonds into the main‐chain chiral liquid crystalline polymer networks.

Endowing artificial advanced materials and systems with biomimetic selfregulatory intelligence is of paramount significance for the development of somatosensory soft robotics and adaptive optoelectronics. Herein, a bioinspired phototropic MXene-reinforced soft tubular actuator is reported that exhibits omnidirectional self-orienting ability and is capable of quickly sensing, continuously tracking, and adaptively interacting with incident light in all zenithal and azimuthal angles of 3D space. The novelty of the soft tubular actuator lies in three aspects: 1) the new polymerizable MXene nanomonomer shows high compatibility with liquid crystal elastomer (LCE) matrices and can be in situ photopolymerized into the polymer networks, thus enhancing the mechanical and photoactuation properties; 2) the distinct hollow and radially symmetrical structure facilitates the actuator with fast photoresponsiveness and phototropic performance through retarding the heat conduction along the radial direction; 3) the MXene-LCE soft tubular actuator simultaneously integrates sensing, actuation, and built-in feedback loop, thus leading to a high light-tracking accuracy and adaptive phototropism like a hollow stem of plants in nature. As a proof-of-concept demonstration, an adaptive photovoltaic system with solar energy harvesting maximization is illustrated. This work can provide insights into the development of artificial intelligent materials toward adaptive optoelectronics, intelligent soft robotics, and beyond.

Chiral nanomaterials with intrinsic chirality or spatial asymmetry at the nanoscale are currently in the limelight of both fundamental research and diverse important technological applications due to their unprecedented physicochemical characteristics such as intense light-matter interactions, enhanced circular dichroism, and strong circularly polarized luminescence. Herein, we provide a comprehensive overview of the state-of-the-art advances in liquid crystal-templated chiral nanomaterials. The chiroptical properties of chiral nanomaterials are touched, and their fundamental design principles and bottom-up synthesis strategies are discussed. Different chiral functional nanomaterials based on liquid-crystalline soft templates, including chiral plasmonic nanomaterials and chiral luminescent nanomaterials, are systematically introduced, and their underlying mechanisms, properties, and potential applications are emphasized. This review concludes with a perspective on the emerging applications, challenges, and future opportunities of such fascinating chiral nanomaterials. This review can not only deepen our understanding of the fundamentals of soft-matter chirality, but also shine light on the development of advanced chiral functional nanomaterials toward their versatile applications in optics, biology, catalysis, electronics, and beyond.

Developing bioinspired camouflage materials that can adaptively change color in the visible and infrared (IR) regions is an intriguing but challenging task. Herein, we report an emerging strategy for fabricating dynamic visible and IR camouflage materials by the controlled in situ growth of novel photopolymerizable blue phase liquid crystals with cubic nanoarchitectures onto highly aligned MXene nanostructured thin films. The resulting MXene-integrated 3D soft photonic crystals exhibit vivid structural colors and reversible switching between a bright colored state and a dark black state under a low DC electric field. As an illustration, proof-of-concept pixelated devices that allow for pixel-controllable electrochromism are demonstrated. Furthermore, a free-standing electrochromic flexible film of such 3D soft photonic crystals is fabricated, where visible electrochromism and thermal camouflage are enabled by leveraging the superior electrothermal conversion and low mid-IR emissivity of MXene nanomaterials.

Endowing a cholesteric liquid crystal elastomer (CLCE) exhibiting a helicoidal nanostructure with dynamically tailorable functionalities is of paramount significance for its emerging applications in diverse fields such as adaptive optics and soft robotics. Here, a mechanochromic, shape‐programmable and self‐healable CLCE is judiciously designed and synthesized through integrating dynamic covalent boronic ester bonds into the main‐chain CLCE polymer network. The circularly polarized reflection of CLCEs can be reversibly and dynamically tuned across the entire visible spectrum by mechanical stretching. Thanks to the introduction of dynamic boronic ester bonds, the CLCEs were found to show robust reprogrammable and self‐healing capabilities. The research disclosed herein can provide new insights into the development of 4D (color and 3D shape) programmable photonic actuators towards bioinspired camouflage, adaptive optical systems, and next‐generation intelligent machines.

In nature, many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots. However, it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying bird. Herein, we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO2 nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the interstices. The resulting soft actuators are found to exhibit brilliant, angle-independent structural color, as well as ultrafast actuation and recovery speeds (a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s, and a recovery time of ~ 0.24 s) in response to acetone vapor. As proof-of-concept illustrations, structural colored soft actuators are applied to demonstrate a blue gripper-like bird’s claw that can capture the target, artificial green tendrils that can twine around tree branches, and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone vapor. The strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines.

Sophisticated sensing and actuation capabilities of many living organisms in nature have inspired scientists to develop biomimetic somatosensory soft robots. Herein, the design and fabrication of homogeneous and highly conductive hydrogels for bioinspired somatosensory soft actuators are reported. The conductive hydrogels are synthesized by in situ copolymerization of conductive surface‐functionalized MXene/Poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonate) ink with thermoresponsive poly(N‐isopropylacrylamide) hydrogels. The resulting hydrogels are found to exhibit high conductivity (11.76 S m−1), strain sensitivity (GF of 9.93), broad working strain range (≈560% strain), and high stability after over 300 loading–unloading cycles at 100% strain. Importantly, shape‐programmable somatosensory hydrogel actuators with rapid response, light‐driven remote control, and self‐sensing capability are developed by chemically integrating the conductive hydrogels with a structurally colored polymer. As the proof‐of‐concept illustration, structurally colored hydrogel actuators are applied for devising light‐driven programmable shape‐morphing of an artificial octopus, an artificial fish, and a soft gripper that can simultaneously monitor their own motions via real‐time resistance variation. This work is expected to offer new insights into the design of advanced somatosensory materials with self‐sensing and actuation capabilities, and pave an avenue for the development of soft‐matter‐based self‐regulatory intelligence via built‐in feedback control that is of paramount significance for intelligent soft robotics and automated machines.

Adaptive Photovoltaics In article number 2201884, Ling Wang, Wei Feng, Quan Li, and co‐workers report bioinspired phototropic MXene‐reinforced soft tubular actuators exhibiting omnidirectional self‐orienting and light‐tracking capability. An adaptive photovoltaic system with solar energy harvesting maximization is conceptualized by integrating the soft tubular actuator with commercially available solar panels.