Nanocellulose-mediated bilayer hydrogel actuators with thermo-responsive, shape memory and self-sensing performances.

Inspired by creatures, abundant stimulus-responsive hydrogel actuators with diverse functionalities have been manufactured for applications in soft robotics. However, constructing a shape memory and self-sensing bilayer hydrogel actuator with high mechanical strength and strong interfacial bonding still remains a challenge. Herein, a novel bilayer hydrogel with a stimulus-responsive TEMPO-oxidized cellulose nanofibers/poly(N-isopropylacrylamide) (TOCN/PNIPAM) layer and a non-responsive TOCN/polyacrylamide (TOCN/PAM) layer is proposed as a thermosensitive actuator. TOCNs as a nano-reinforced phase provide a high mechanical strength and endow the hydrogel actuator with a strong interfacial bonding. Due to the incorporation of TOCNs, the TOCN/PNIPAM hydrogel exhibits a high compressive strength (~89.2 kPa), elongation at break (~170.7 %) and tensile strength (~24.0 kPa). The prepared PNIPAM/TOCN/PAM hydrogel actuator performs the roles of an encapsulation, jack, temperature-controlled fluid valve and temperature-control manipulator. The incorporation of Fe3+ further endows the bilayer hydrogel actuator with a synergistic performance of shape memory and temperature-driven, which can be used as a temperature-responsive switch to detect ambient temperature. The PNIPAM/TOCN/PAM-Fe3+ conductive hydrogel can be assembled into a flexible sensor and generate sensing signals when driven by temperature changes to achieve real-time feedback. This research may lead to new insights into the design and manufacturing of intelligent flexible soft robots.

Hierarchically core-shell structured nanocellulose/carbon nanotube hybrid aerogels for patternable, self-healing and flexible supercapacitors.

The flexible and self-healing supercapacitors (SCs) are considered to be promising smart energy storage devices. Nevertheless, the SCs integrated with flexibility, lightweight, pattern editability, self-healing capabilities and desirable electrochemical properties remain a challenge. Herein, an all-in-one self-healing SC fabricated with the free-standing hybrid film (TCMP) composed of the 2,2,6,6-tetramethylpiperidin-1-yloxy-oxidized cellulose nanofibers (TOCNs) carried carbon nanotubes (CNTs), manganese dioxide (MnO2) and polyaniline (PANI) as the electrode, polyvinyl alcohol/sulfuric acid (PVA/H2SO4) gel as the electrolyte and dynamically cross-linked cellulose nanofibers/PVA/sodium tetraborate decahydrate (CNF/PB) hydrogel as the self-healing electrode matrix is developed. The TCMP film electrodes are fabricated through a facile in-situ polymerization of MnO2 and PANI in TOCNs-dispersed CNTs composite networks, exhibiting lightweight, high electrical conductivity, flexibility, pattern editability and excellent electrochemical properties. Benefited from the hierarchically porous structure and high mechanical properties of TOCNs, excellent electrical conductivity of CNTs and the desirable synergistic effect of pseudocapacitance induced by MnO2 and PANI, the assembled SC with an interdigital structure demonstrated a high areal capacitance of 1108 mF cm-2 at 2 mA cm-2, large areal energy density of 153.7 µWh cm-2 at 1101.7 µW cm-2. A satisfactory bending cycle performance (capacitance retention up to 95 % after 200 bending deformations) and self-healing characteristics (∼90 % capacitance retention after 10 cut/repair cycles) are demonstrated for the TCMP-based symmetric SC, delivering a feasible strategy for electrochemical energy storage devices with excellent performance, designable patterns and desirable safe lifespan.

Electrochemical Hydrophobic Tri-layer Interface Rendered Mechanically Graded Solid Electrolyte Interface for Stable Zinc Metal Anode.

The aqueous zinc-ion battery is promising as grid scale energy storage device, but hindered by the instable electrode/electrolyte interface. Herein, we report the lean-water ionic liquid electrolyte for aqueous zinc metal batteries. The lean-water ionic liquid electrolyte creates the hydrophobic tri-layer interface assembled by first two layers of hydrophobic OTF- and EMIM+ and third layer of loosely attached water, beyond the classical Gouy-Chapman-Stern theory based electrochemical double layer. By taking advantage of the hydrophobic tri-layer interface, the lean-water ionic liquid electrolyte enables a wide electrochemical working window (2.93 V) with relatively high zinc ion conductivity (17.3 mS/cm). Furthermore, the anion crowding interface facilitates the OTF- decomposition chemistry to create the mechanically graded solid electrolyte interface layer to simultaneously suppress the dendrite formation and maintain the mechanical stability. In this way, the lean-water based ionic liquid electrolyte realizes the ultralong cyclability of over 10000 cycles at 20 A/g and at practical condition of N/P ratio of 1.5, the cumulated areal capacity reach 1.8 Ah/cm2 , which outperforms the state-of-the-art zinc metal battery performance. Our work highlights the importance of the stable electrode/electrolyte interface stability, which would be practical for building high energy grid scale zinc-ion battery.

Biomass-Derived Carbon Aerogels for ORR/OER Bifunctional Oxygen Electrodes.

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial electrochemical reactions that play vital roles in energy conversion and storage technologies, such as fuel cells and metal-air batteries. Typically, noble-metal-based catalysts are required to enhance the sluggish kinetics of the ORR and OER, but their high costs restrict their practical commercial applications. Thus, highly active and strong non-noble metal catalysts are essential to address the cost and durability challenge. Based on previous research, carbon-based catalysts may present the best alternatives to these precious metals in the future owing to their affordability, very large surface areas, and superior mechanical and electrical qualities. In particular, carbon aerogels prepared using biomass as the precursors are referred to as biomass-derived carbon aerogels. They have sparked broad attention and demonstrated remarkable performance in the energy conversion and storage sectors as they are ecologically beneficial, affordable, and have an abundance of precursors. Therefore, this review focuses on various nanostructured materials based on biomass-derived carbon aerogels as ORR/OER catalysts, including metal atoms, metal compounds, and alloys.

Construction of Multifunctional Hierarchical Biofilms for Highly Sensitive and Weather-Resistant Fire Warning.

Multifunctional biofilms with early fire-warning capabilities are highly necessary for various indoor and outdoor applications, but a rational design of intelligent fire alarm films with strong weather resistance remains a major challenge. Herein, a multiscale hierarchical biofilm based on lignocellulose nanofibrils (LCNFs), carbon nanotubes (CNTs) and TiO2 was developed through a vacuum-assisted alternate self-assembly and dipping method. Then, an early fire-warning system that changes from an insulating state to a conductive one was designed, relying on the rapid carbonization of LCNFs together with the unique electronic excitation characteristics of TiO2. Typically, the L-CNT-TiO2 film exhibited an ultrasensitive fire-response signal of ~0.30 s and a long-term warning time of ~1238 s when a fire disaster was about to occur, demonstrating a reliable fire-alarm performance and promising flame-resistance ability. More importantly, the L-CNT-TiO2 biofilm also possessed a water contact angle (WCA) of 166 ± 1° and an ultraviolet protection factor (UPF) as high as 2000, resulting in excellent superhydrophobicity, antifouling, self-cleaning as well as incredible anti-ultraviolet (UV) capabilities. This work offers an innovative strategy for developing advanced intelligent films for fire safety and prevention applications, which holds great promise for the field of building materials.

Functionalized cellulose nanofibrils based supramolecular system-assisted molding enabled strong, antibacterial chitosan bioplastics.

Bioplastics are considered as potential alternatives to non-renewable and non-biodegradable petroleum-based plastics. Inspired by ionic and amphiphilic properties of mussel protein, we proposed a versatile and facile strategy for the fabrication of a high-performance chitosan (CS) composite film. This technique incorporates a cationic hyperbranched polyamide (QHB) and a supramolecular system based on the lignosulphonate (LS)-functionalized cellulose nanofibrils (CNF) (LS@CNF) hybrids. The cationic QHB was synthesized by a one-step process from hyperbranched polyamide and quaternary ammonium salt. Meanwhile, the functional LS@CNF hybrids act as a well-dispersed and rigid cross-linked domain in CS matrix. Owing to the interconnected hyperbranched and enhanced supramolecular network, the toughness and tensile strength of the CS/QHB/LS@CNF film simultaneously increased to 19.1 MJ/m3 and 50.4 MPa, 170.2 % and 72.6 % higher than the pristine CS film. Additionally, the functional QHB/LS@CNF hybrids endow the films with superior antibacterial activity, water resistance, UV shielding, and thermal stability. This bioinspired strategy provides a novel and sustainable method for the production of multifunctional CS films.

3D Printed Nitrogen-Doped Thick Carbon Architectures for Supercapacitor: Ink Rheology and Electrochemical Performance.

The 3D printing technique offers huge opportunities for customized thick-electrode designs with high loading densities to enhance the area capacity in a limited space. However, key challenges remain in formulating 3D printable inks with exceptional rheological performance and facilitating electronic/ion transport in thick bulk electrodes. Herein, a hybrid ink consisting of woody-derived cellulose nanofibers (CNFs), multiwalled carbon nanotubes (MWCNTs), and urea is formulated for the 3D printing nitrogen-doped thick electrodes, in which CNFs serve as both dispersing and thickening agents for MWCNTs, whereas urea acts as a doping agent. By systematically tailoring the concentration-dependent rheological performance and 3D printing process of the ink, a variety of gel architectures with high geometric accuracy and superior shape fidelity are successfully printed. The as-printed gel architecture is then transformed into a nitrogen-doped carbon block with a hierarchical porous structure and superior electrochemical performance after freeze-drying and annealing treatments. Furthermore, a quasi-solid-state symmetric supercapacitor assembled with two interdigitated carbon blocks obtained by a 3D printing technique combined with a nitrogen-doping strategy delivers an energy density of 0.10 mWh cm-2 at 0.56 mW cm-2 . This work provides guidance for the formulation of the printable ink used for 3D printing of high-performance thick carbon electrodes.

Microplastic remediation technologies in water and wastewater treatment processes: Current status and future perspectives.

Microplastics (MPs) are a type of contaminants produced during the use and disposal of plastic products, which are ubiquitous in our lives. With the high specific surface area and strong hydrophobicity, MPs can adsorb various hazardous microorganisms and chemical contaminants from the environment, causing irreversible damage to our humans. It is reported that the MPs have been detected in infant feces and human blood. Therefore, the presence of MPs has posed a significant threat to human health. It is critically essential to develop efficient, scalable and environmentally-friendly methods to remove MPs. Herein, recent advances in the MPs remediation technologies in water and wastewater treatment processes are overviewed. Several approaches, including membrane filtration, adsorption, chemically induced coagulation-flocculation-sedimentation, bioremediation, and advanced oxidation processes are systematically documented. The characteristics, mechanisms, advantages, and disadvantages of these methods are well discussed and highlighted. Finally, the current challenges and future trends of these methods are proposed, with the aim of facilitating the remediation of MPs in water and wastewater treatment processes in a more efficient, scalable, and environmentally-friendly way.

Flexible environment-tolerant electroluminescent devices based on nanocellulose-mediated transparent electrodes.

Stretchable electroluminescent (EL) devices show great potential for wearable displays. However, the integration of stretchability, flexibility, temperature-tolerance, waterproofness and biocompatibility into a single EL device remains a challenge. Herein, we report a facile full solution-process method for a novel EL device consisting of a dielectric luminescent layer sandwiched between two silver nanowires-cellulose nanocrystals with II crystalline allomorphs/polydopamine-polydimethylsiloxane (CNC II-AgNWs/PDA-PDMS) electrodes. CNC II is used as a green dispersant, film-forming agent and antioxidant to improve the optical, electrical, mechanical and antioxidant properties of the electrodes. The electrodes exhibit a smooth surface, low sheet resistance (~11 Ω sq-1), high transparency (~79.2 %), ideal stretchability (~100 % strain) and excellent inoxidizability. The assembled EL devices with outstanding tensile stability and fatigue resistance demonstrate excellent luminance, flexibility and stretchability underwater and at extreme temperatures, as well as intrinsic biocompatibility. Our multifunctional EL devices with outstanding integrated properties provide new insights for the next-generation flexible electronics.

Multilayered Nanocomposites Prepared through Quadruple-Layering Approach towards Enhanced Mechanical Performance.

Multilayered materials are widely studied due to their special structures and great properties, such as their mechanical ones. In this paper a novel and effective technique, a quadruple-layering approach, was used to fabricate multilayered materials. This approach increases the number of layers rapidly via simple operations. Materials with 4, 16, and 64 layers with alternating layers of polypropylene and nanocomposites were fabricated using this approach, and their film morphology and mechanical properties were studied. The influence of the number of layers on the mechanical properties of the materials and the relationship between the mechanical properties of each material were investigated. The results illustrated that the tensile modulus and strength were enhanced and elongation at the break increased when the layer numbers of the multilayered materials increased. However, this approach has a defect in that as the layer number increases, the layer thickness was not uniform, thus restricting the improvement of properties. This may need to be further studied in future work.

Synergic Effect of Dendrite-Free and Zinc Gating in Lignin-Containing Cellulose Nanofibers-MXene Layer Enabling Long-Cycle-Life Zinc Metal Batteries.

Uncontrollable zinc dendrite growth and parasitic reactions have greatly hindered the development of high energy and long life rechargeable aqueous zinc-ion batteries. Herein, the synergic effect of a bifunctional lignin-containing cellulose nanofiber (LCNF)-MXene (LM) layer to stabilize the interface of zinc anode is reported. On one hand, the LCNF provides enough strength (43.7 MPa) at relative low porosity (52.2%) to enable the diffusion limited dendrite suppression, while, on the other hand, the MXene serves as a zinc gating layer, facilitating the zinc ion mobility, restricting the active water/anions from degradation in the electrode/electrolyte interface, and epitaxially guiding zinc deposition along (002) plane. Benefiting from the synergic effect of diffusion limited dendrite suppression and zinc gate, the LM layer enabled a high coulombic efficiency (CE) of 98.9% with a low overpotential of 43.1 mV at 1 mA cm-2 in Zn//Cu asymmetric cells. More importantly, Zn//MnO2 full cells with the LM layer achieve a high-capacity retention of 90.0% for over 1000 cycles at 1 A g-1 , much higher than the full cell without the protective layer (73.9% over 500 cycles). The work provides a new insight in designing a dendrite-free zinc anode for long-cycle-life batteries.

Patternable Nanocellulose/Ti3C2Tx Flexible Films with Tunable Photoresponsive and Electromagnetic Interference Shielding Performances.

Nanocellulose-mediated MXene composites have attracted widespread attention in the fields of sustainable energy, wearable sensors, and electromagnetic interference (EMI) shielding. However, the effects of different nanocelluloses on the multifunctional properties of nanocellulose/Ti3C2Tx composites still need further exploration. Herein, we use three types of nanocelluloses, including bacterial cellulose (BC), cellulose nanocrystals (CNCs), and 2,2,6,6-tetramethylpiperidin-1-yloxy (TEMPO)-oxidized cellulose nanofibers (TOCNs), as intercalation to link Ti3C2Tx nanosheets via a self-assembly process, improving the dispersibility, film-forming ability, mechanical properties, and multifunctional performances of nanocelluloses/Ti3C2Tx hybrids through electrostatic forces and hydrogen bonding. The optimized ultrathin (∼40 µm) TOCN/Ti3C2Tx film integrates excellent tensile strength (∼98.89 MPa), long-term stability (during deformation and water erosion), favorable photoelectric response (photosensitivity up to 2620%), and temperature response (reaching 163 °C in only 12 s). Laser-cutting patterned TOCN/Ti3C2Tx films are assembled into flexible multifunctional electronics, exhibiting splendid photoresponse performances and tunable electromagnetic energy shielding capability (>96.4%) related to the variation of water content at the film-gel electrolyte interface. Multifunctional patterned devices based on TOCN/Ti3C2Tx composite films provide a novel pathway to rationally design wearable EMI devices with photoelectric response and photothermal conversion.

Thermal and flame-retardant properties of multilayered composites prepared through novel multilayering approach.

Thermal and flame-retardant properties of traditional composites have limitations that are not satisfied for the various applications. Multilayered materials have great potential to improve material properties. The present paper focused on designing new multilayering approach to fabricate flame retardant multilayered materials with a very basic instrument and several simple steps. Montmorillonite nanoparticles filled maleic anhydride grafted polypropylene composites were prepared by the melt-blending method, and the multilayered composites with polypropylene alternating multilayers were fabricated by the quadruple-layering approach. The multilayer structure was characterized by the scanning electron microscopy/energy dispersive spectrometer. The influence of layer structure on the thermal stability, thermal conductivity and flame-retardant properties was investigated by the comparison with the conventional composites. Multilayered composites showed enhanced flame-retardant properties with lower peak heat release rate and better char formation compared to conventional composites with the same mass fraction of montmorillonite. Multilayered composites had higher mass fraction of montmorillonite in filled layers and no fillers in other layers, which caused the unequal distribution of montmorillonite, resulting in changes of thermal and flame-retardant properties of the materials especially in the perpendicular direction to the film surface. This study demonstrates a unique multilayering approach that has potential to be used in variety applications such as food and medical packaging.

Lignin-containing cellulose nanofibers made with microwave-aid green solvent treatment for magnetic fluid stabilization.

Lignin-containing cellulose nanofibers (LCNFs), prepared from energy cane bagasse (ECB) using microwave-assisted natural deep eutectic solvent (MW-NADES) pretreatment combined with microfluidization, are utilized as stabilizing agents for magnetic particles (MNPs) in magnetorheological fluids (MRFs). The as-prepared LCNFs helped suspend negatively charged MNPs in MRFs effectively due to the presence of physically entangled network of LCNFs and the electrostatic repulsion between LCNFs and MNPs. Consequently, the presence of LCNFs increased the viscosity, yield stress and dynamic moduli of MRFs within the entire magnetic field range (0-1 T). Moreover, the as-developed LCNF-MRFs exhibited superior magnetorheological properties, i.e., widely controllable viscosity, yield stress and dynamic moduli, rapid magnetic response, good reversibility and outstanding cycling stability. This work demonstrates the sustainable, ultrafast production of LCNFs from cellulosic biomass using MW-NADES for MRF stabilization, paving the way for the development of high-performance, and eco-friendly MRFs.

Lightweight and anisotropic cellulose nanofibril/rectorite composite sponges for efficient dye adsorption and selective separation.

Constructing lightweight and porous adsorbents which can effectively remove dye contaminants is of great significance in the field of the sewage treatment. In this work, anisotropic cellulose nanofibril (CNF) composite sponges assisted by rectorites are fabricated through directional freeze-drying. The resulted composite sponge exhibits the superior saturated adsorption capacity and removal efficiency of 120.0 mg/g and 96.1% for methylene blue (MB), respectively, which is better than the pure CNF sponge and rectorite powders. This is attributed to the strong electrostatic interaction between CNFs and MB, and good cation exchange property of rectorites inside the three-dimensional (3D) highly porous composite sponge. The MB adsorption process of the composite sponge fits to the pseudo-second-order kinetic model and the Langmuir isotherm model well, which is affected by both boundary layer and intraparticle diffusion, resulting in a theoretical maximum adsorption capacity of 214.6 mg/g. Moreover, it also possesses a selective adsorption capacity for anionic and cationic dyes, which is expected to realize the separation treatment of different dyes according to actual application requirements.

Advanced nanocellulose-based gas barrier materials: Present status and prospects.

Nanocellulose based gas barrier materials have become an increasingly important subject, since it is a widespread environmentally friendly natural polymer. Previous studies have shown that super-high gas barrier can be achieved with pure and hierarchical nanocellulose films fabricated through simple suspension or layer-by-layer technique either by itself or incorporating with other polymers or nanoparticles. Improved gas barrier properties were observed for nanocellulose-reinforced composites, where nanocellulose partially impermeable nanoparticles decreased gas permeability effectively. However, for nanocellulose-based materials, the higher gas barrier performance is jeopardized by water absorption and shape deformation under high humidity conditions which is a challenge for maintaining properties in material applications. Thus, numerous investigations have been done to solve the problem of water absorption in nanocellulose-based materials. In this literature review, gas barrier properties of pure, layer-by-layer and composite nanocellulose films are investigated. The possible theoretical gas barrier mechanisms are described, and the prospects for nanocellulose-based materials are discussed.

Anisotropic cellulose nanofibril composite sponges for electromagnetic interference shielding with low reflection loss.

With the development of the electronic industry bringing convenience to people, a series of caused electromagnetic pollution problems (e.g., electromagnetic interference (EMI)) have recently also become urgent tasks. In this work, an anisotropic composite sponge consisting of cellulose nanofibrils (CNFs) and chemical co-precipitated silver nanowire (AgNW)@Fe3O4 composites was successfully prepared. Due to the introduction of anisotropic structures and the synergistic effect among CNFs, AgNWs, and Fe3O4, this composite sponge exhibited low density (16.76 mg/cm3), good saturation magnetization (4.21 emu/g) and electrical conductivity (0.02 S/cm), and anisotropic EMI shielding ability. By adjusting the proportion (1:0.3) between AgNWs and Fe3O4 and their loading (0.15 vol%) inside the sponge, the reflection loss of the sponge with the improved interface impedance mismatch was only 2.3 dB, accounting for 7.2% of the total loss. It is expected to become a promising EMI shielding material, especially for effectively alleviating the secondary reflection EM pollution.

Liquid Transport and Real-Time Dye Purification via Lotus Petiole-Inspired Long-Range-Ordered Anisotropic Cellulose Nanofibril Aerogels.

Nowadays, large-scale oriented functional porous materials have been sought after by researchers. However, regulation of the long-range uniform and oriented structures of the material remains a challenge. Herein, ultralong anisotropic cellulose nanofibril (CNF) aerogels with uniformly ordered structures of pore walls inspired by lotus petioles were constructed by applying external speeds to counterbalance the growth driving forces of ice crystals. Based on the growth law of ice crystals, the ice crystals grew at a stable rate when the applied external speed was 0.04 mm/s, ensuring the consistent orientation of the large-scale CNF aerogel. The aerogel exhibited a rapid long-range directional transport ability to different liquid solvents, delivering ethanol up to 40 mm from bottom to top within 50 s. Moreover, by introducing rectorites with good cation-exchange properties, the resulting long-range composite possessed an enhanced adsorption capacity for methylene blue. Furthermore, aerogel successfully achieved real-time dye purification at a long distance, such as fast dye adsorption or selective adsorption. This flexible and straightforward strategy of fabricating ultralong oriented CNF aerogel materials is expected to promote the development of functional aerogels in directional liquid transport and sewage treatment.

Inherently Conductive Poly(dimethylsiloxane) Elastomers Synergistically Mediated by Nanocellulose/Carbon Nanotube Nanohybrids toward Highly Sensitive, Stretchable, and Durable Strain Sensors.

With the rapid development of soft electronics, flexible and stretchable strain sensors are highly desirable. However, coupling of high sensitivity and stretchability in a single strain sensor remains a challenge. Herein, a kind of conductive elastomer is constructed with poly(dimethylsiloxane) (PDMS) and silylated cellulose nanocrystal (SCNC)/carbon nanotube (CNT) nanohybrids through a facile one-pot solution-casting method. The hydrophobic SCNCs can effectively facilitate the dispersion of CNTs in PDMS and synergistically improve the interfacial compatibility between CNTs and the PDMS matrix, resulting in favorable stress and electron transfer in the polymer network. Due to the outstanding electrical conductivity of CNTs and the excellent dispersity and high mechanical performance of SCNCs, combined with the good compatibility between SCNC-mediated carbon nanotubes (SCNC-CNTs) and PDMS, the resulting composite elastomer (SCNC-CNT/PDMS) shows high electrical conductivity (∼2.77 S m-1), tensile strength (∼5.72 MPa), and fatigue resistance properties. The strain sensor assembled by SCNC-CNT/PDMS demonstrates a high strain range above 100%, appealing strain sensitivity with a gauge factor of 37.11 at 50-100% strain, and long-term stability and durability, which is capable of monitoring both real-time human motions and acoustic vibrations. This work paves a new way for the design and controllable preparation of flexible and stretchable conductive elastomers, demonstrating promising applications in wearable devices and intelligent electronics.

Self-Recovery, Fatigue-Resistant, and Multifunctional Sensor Assembled by a Nanocellulose/Carbon Nanotube Nanocomplex-Mediated Hydrogel.

Flexible sensors have attracted great research interest due to their applications in artificial intelligence, wearable electronics, and personal health management. However, due to the inherent brittleness of common hydrogels, preparing a hydrogel-based sensor integrated with excellent flexibility, self-recovery, and antifatigue properties still remains a challenge to date. In this study, a type of physically and chemically dual-cross-linked conductive hydrogels based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofiber (TOCN)-carrying carbon nanotubes (CNTs) and polyacrylamide (PAAM) matrix via a facial one-pot free-radical polymerization is developed for multifunctional wearable sensing application. Inside the hierarchical gel network, TOCNs not only serve as the nanoreinforcement with a toughening effect but also efficiently assist the homogeneous distribution of CNTs in the hydrogel matrix. The optimized TOCN-CNT/PAAM hydrogel integrates high compressive (∼2.55 MPa at 60% strain) and tensile (∼0.15 MPa) strength, excellent intrinsic self-recovery property (recovery efficiency >92%), and antifatigue capacity under both cyclic stretching and pressing. The multifunctional sensors assembled by the hydrogel exhibit both high strain sensitivity (gauge factor ≈11.8 at 100-200% strain) and good pressure sensing ability over a large pressure range (0-140 kPa), which can effectively detect the subtle and large-scale human motions through repeatable and stable electrical signals even after 100 loading-unloading cycles. The comprehensive performance of the TOCN-CNT/PAAM hydrogel-based sensor is superior to those of most gel-based sensors previously reported, indicating its potential applications in multifunctional sensing devices for healthcare systems and human motion monitoring.