Herein, we report near‐infrared (NIR) light‐driven shape‐morphing of programmable MXene‐containing anisotropic hydrogel actuators that are fabricated through in situ free‐radical copolymerization of a judiciously designed MXene nanomonomer with thermosensitive hydrogel network. A low electric field (few V mm−1) was found to enable a spatial distribution of MXene nanosheets and hence introduce anisotropy into the hydrogel network. Programmable anisotropic hydrogel actuators were developed by controlling ITO electrode pattern, direct‐current (DC) electric field direction and mask‐assisted photopolymerization. As a proof‐of‐concept, we demonstrate NIR light‐driven shape morphing of the MXene‐containing anisotropic hydrogel into various shapes and devise a four‐arm soft gripper that can perform distinct photomechanical functions such as grasping, lifting/lowering down and releasing an object upon sequential NIR light exposure.

Sophisticated soft matter engineering has been endorsed as an emerging paradigm for developing untethered soft robots with built-in electronic functions and biomimetic adaptation capacities. However, the integration of flexible electronic...

simplicity of design. [10,11] Several requirements such as high stretchability, flexibility, a wide working strain range from a subtle region to a large region, durability, lightweight, and low energy consumption should be fulfilled for wearable devices. [12] To achieve the stretchable flexible devices, studies on stretchable elastomeric substrates consisting of highly conductive fillers have been reported. [13,14] Ding et al. demonstrated a scalable and facile preparation of the electrospun polyurethane (PU) nonwoven dip-coated with the conducting polymer poly(3,4-ethylened ioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), which possessed adjustable electrical conductivity in the range of 30-200 S m −1 and large stretchability of 400%. [15] Lu et al. reported a sandwich-structured strain sensor with a gauge factor (GF) of 12.9 (at 20% strain) and a sensing range of 0-50% based on attaching the silver nanowires (AgNWs) on the thermoplastic polyurethane electrospun membrane (TPUEM) by filtration, followed by spin-coating using the liquid polydimethylsiloxane (PDMS). [16] Recently, electrospinning has become an effective, facile, and scalable technique for preparation of micro/nanofibers applied in wide applications. [17][18][19] The electrospun fibers own numerous advantages such as large specific surface area, high porosity, fine diameter, and commendable mechanical flexibility, which is an ideal base material for functional composites. [20,21] Especially, thermoplastic polyurethane (TPU) was easily electrospun into fibrous membrane which displayed outstanding stretchability, flexibility, and mechanical strength. [22,23] However, the pristine TPUEM has no conductivity and cannot be serving as sensing materials solely. Diverse conductive fillers incorporate into TPUEM to be developed as stretchable strain sensors. Yan et al. fabricated electrospun TPU fiber yarns successively decorated with multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) for wearable strain sensors. [24] Wang et al. developed a novel strain sensor with an excellent 3D conductive network based on reduced graphene oxide (RGO)-decorated TPU mats. [25] Tian fabricated electrospun PU/polyaniline nanofibrous mat by in situ chemical polymerization of aniline monomers on the surface of electrospun PU nanofiber substrate for wearable device. [26] However, it is quite difficult to Highly stretchable, conductive, and sensitive strain-sensing materials have aroused wide interest owing to their potential in wearable devices. A facile and scalable method to fabricate a carbon-nanotube-(CNT-) bridged silver nanoparticles (AgNPs) strain sensor based on thermoplastic polyurethane electrospun membrane (TPUEM), which exhibits a large strain range with a high gauge factor simultaneously, is demonstrated. It exhibits a high stretchability with large workable strain range of up to 550%, high gauge factor of 7066, good durability over 1000 cycles, and comparable stability under various strains. Importantly, it can be used for human mo...

Nanocellulose is currently in the limelight of extensive research from fundamental science to technological applications owing to its renewable and carbon-neutral nature, superior biocompatibility, tailorable surface chemistry, and unprecedented optical and mechanical properties. Herein, an up-to-date account of the recent advancements in nanocellulose-derived functional materials and their emerging applications in areas of chiral photonics, soft actuators, energy storage, and biomedical science is provided. The fundamental design and synthesis strategies for nanocellulose-based functional materials are discussed. Their unique properties, underlying mechanisms, and potential applications are highlighted. Finally, this review provides a brief conclusion and elucidates both the challenges and opportunities of the intriguing nanocellulose-based technologies rooted in materials and chemistry science. This review is expected to provide new insights for nanocellulose-based chiral photonics, soft robotics, advanced energy, and novel biomedical technologies, and promote the rapid development of these highly interdisciplinary fields, including nanotechnology, nanoscience, biology, physics, synthetic chemistry, materials science, and device engineering.

No abstract

No abstract

Molybdenum disulfide has been one of the most studied hydrogen evolution catalyst materials in recent years, but its disadvantages, such as poor conductivity, hinder its further development. Here, we employ the common hydrothermal method, followed by an additional solvothermal method to construct an uncommon molybdenum disulfide with two crystal forms of 1T and 2H to improve catalytic properties. The low overpotential (180 mV) and small Tafel slope (88 mV/dec) all indicated that molybdenum disulfide had favorable catalytic performance for hydrogen evolution. Further conjunctions revealed that the improvement of performance was probably related to the structural changes brought about by the 1T phase and the resulting sulfur vacancies, which could be used as a reference for the further application of MoS2.

No abstract