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1.
Flexible electronic devices (FEDs) based on hydrogels are attracting increasing interest, but the fabrication of hydrogels for FEDs with adhesiveness and high robustness in harsh-temperature conditions and long-term use remains a challenge. Herein, glutinous-rice-inspired adhesive organohydrogels are developed by introducing amylopectin into a copolymer network through a “one-pot” crosslinking procedure in a glycerol–water mixed solvent containing potassium chloride as the conductive ingredient. The organohydrogels exhibit excellent transparency (>90%), conductivity, stretchability, tensile strength, adhesiveness, anti-freezing property, and moisture retention ability. The wearable strain sensor assembled from the organohydrogels achieves a wide working range, high sensitivity (gauge factor: 8.82), low response time, and excellent reversibility, and properly responds in harsh-temperature conditions and long-time storage (90 days). The strain sensor is further integrated with a Bluetooth transmitter and receiver for fabricating wireless wearable sensors. Notably, a sandwich-structured capacitive pressure sensor with organohydrogels containing reliefs as electrodes records a new gauge factor of 9.43 kPa?1 and achieves a wide response range, low detection limit, and outstanding reversibility. Furthermore, detachable and durable batteries and all-in-one supercapacitors are also fabricated utilizing the organohydrogels as electrolytes. Overall, this work offers a strategy to fabricate adhesive organohydrogels for robust FEDs toward wearable sensing, power supply, and energy storage.  相似文献   

2.
Fluidic soft sensors have been widely used in wearable devices for human motion capturing. However, thus far, the biocompatibility of the conductive liquid, the linearity of the sensing signal, and the hysteresis between the loading and release processes have limited the sensing quality as well as the applications of these sensors. In this paper, silicone based strain and force sensors composed of a novel biocompatible conductive liquid (potassium iodide and glycerol solution) are introduced. The strain sensors exhibit negligible hysteresis up to 5 Hz, with a gauge factor of 2.2 at 1 Hz. The force sensors feature a novel multifunctional layered structure, with microcylinder‐filled channels to achieve high linearity, low hysteresis (5.3% hysteresis at 1 Hz), and good sensitivity (100% resistance increase at a 5 N load). The sensors' gauge factors are stable at various temperatures and humidity levels. These biocompatible, low hysteresis, and high linearity sensors are promising for safe and reliable diagnostic devices, wearable motion capture, and compliant human–computer interfaces.  相似文献   

3.
Functional electrical devices have promising potentials in structural health monitoring system, human‐friendly wearable interactive system, smart robotics, and even future multifunctional intelligent room. Here, a low‐cost fabrication strategy to efficiently construct highly sensitive graphite‐based strain sensors by pencil‐trace drawn on flexible printing papers is reported. The strain sensors can be operated at only two batteries voltage of 3 V, and can be applied to variously monitoring microstructural changes and human motions with fast response/relaxation times of 110 ms, a high gauge factor (GF) of 536.6, and high stability >10 000 bending–unbending cycles. Through investigation of service behaviors of the sensors, it is found that the microcracks occur on the surface of the pencil‐trace and have a major influence on the functions of the strain sensors. These performances of the strain sensor attain and even surpass the properties of recent strain sensing devices with subtle design of materials and device architectures. The pen‐on‐paper (PoP) approach may further develop portable, environmentally friendly, and economical lab‐on‐paper applications and offer a valuable method to fabricate other multifunctional devices.  相似文献   

4.
Simultaneously developing protective electronics film for multi-spectra, including the radar, infrared (IR), and visible ranges, for both the military and civilian sectors is extremely challenging. The existing multi-spectra-compatible materials mainly concentrate on either the radar/IR or IR/visible bands, trailing the rapid evolution of advanced devices for monitoring electromagnetic signals. Here, it is designed and fabricated an ultra-thin MXene-based composite film (20 µm) containing black phosphorus (BP) and Ni chains (M-B-M(Ni)) with integrated highly efficient thermal IR stealth, visible light absorption, and electromagnetic wave shielding. M-B-M(Ni) exhibits an extremely low IR emissivity of 0.1, decreasing the radiation temperature difference between the surrounding environment and target device. BP offers a high solar absorptance of 80%, which guarantees energy conversion from visible light to heat. Moreover, the absorption proportion of the electromagnetic shielding effectiveness for M-B-M(Ni) is 16% higher than that of pure MXene films (68.7%), owing to the improved magnetic loss by decoration with magnetic Ni chains. Due to the combined merits of MXene, BP, and Ni chains, M-B-M(Ni) opens an avenue for the construction of advanced multi-spectra compatible materials for versatile applications in thermal IR stealth, electromagnetic wave shielding, and energy transformation.  相似文献   

5.
Currently, most customized hydrogels can only be processed via extrusion-based 3D printing techniques, which is limited by printing efficiency and resolution. Here, a simple strategy for the rapid fabrication of customized hydrogels using a photocurable 3D printing technique is presented. This technique has been rarely used because the presence of water increases the molecular distance between the polymer chains and reduces the monomer polymerization rate, resulting in the failure of rapid solid-liquid separation during printing. Although adding cross-linkers to printing inks can effectively accelerate 3D cross-linked network formation, chemical cross-linking may result in reduced toughness and self-healing ability of the hydrogel. Therefore, an interpenetrated-network hydrogel based on non-covalent interactions is designed to form physical cross-links, affording fast solid-liquid separation. Poly(acrylic acid (AA)-N-vinyl-2-pyrrolidone (NVP)) and carboxymethyl cellulose (CMC) are cross-linked via Zn2+-ligand coordination and hydrogen bonding; the resulting mixed AA-NVP/CMC solution is used as the printing ink. The printed poly(AA-NVP/CMC) hydrogel exhibited high tensile toughness (3.38 MJ m−3) and superior self-healing ability (healed stress: 81%; healed strain: 91%). Some objects like manipulator are successfully customized by photocurable 3D printing using hydrogels with high toughness and complex structures. This high-performance hydrogel has great potential for application in flexible wearable sensors.  相似文献   

6.
Conductive hydrogels are attracting tremendous interest in the field of flexible and wearable soft strain sensors because of their great potential in electronic skins, and personalized healthcare monitoring. However, conventional conductive hydrogels using pure water as the dispersion medium will inevitably freeze at subzero temperatures, resulting in the diminishment of their conductivity and mechanical properties; meanwhile, even at room temperature, such hydrogels suffer from the inevitable loss of water due to evaporation, which leads to a poor shelf‐life. Herein, an antifreezing, self‐healing, and conductive MXene nanocomposite organohydrogel (MNOH) is developed by immersing MXene nanocomposite hydrogel (MNH) in ethylene glycol (EG) solution to replace a portion of the water molecules. The MNH is prepared from the incorporation of the conductive MXene nanosheet networks into hydrogel polymer networks. The as‐prepared MNOH exhibits an outstanding antifreezing property (?40 °C), long‐lasting moisture retention (8 d), excellent self‐healing capability, and superior mechanical properties. Furthermore, this MNOH can be assembled as a wearable strain sensor to detect human biologic activities with a relatively broad strain range (up to 350% strain) and a high gauge factor of 44.85 under extremely low temperatures. This work paves the way for potential applications in electronic skins, human?machine interactions, and personalized healthcare monitoring.  相似文献   

7.
The wearable revolution is already present in society through numerous gadgets. However, the contest remains in fully deployable wearable (bio)chemical sensing. Its use is constrained by the energy consumption which is provided by miniaturized batteries, limiting the autonomy of the device. Hence, the combination of materials and engineering efforts to develop sustainable energy management is paramount in the next generation of wearable self-powered electrochemical devices (WeSPEDs). In this direction, this review highlights for the first time the incorporation of innovative energy harvesting technologies with top-notch wearable self-powered sensors and low-powered electrochemical sensors toward battery-free and self-sustainable devices for health and wellbeing management. First, current elements such as wearable designs, electrochemical sensors, energy harvesters and storage, and user interfaces that conform WeSPEDs are depicted. Importantly, the bottlenecks in the development of WeSPEDs from an analytical perspective, product side, and power needs are carefully addressed. Subsequently, energy harvesting opportunities to power wearable electrochemical sensors are discussed. Finally, key findings that will enable the next generation of wearable devices are proposed. Overall, this review aims to bring new strategies for an energy-balanced deployment of WeSPEDs for successful monitoring of (bio)chemical parameters of the body toward personalized, predictive, and importantly, preventive healthcare.  相似文献   

8.
Photochromic materials have recently received strong interest for the development of wearable ultraviolet (UV) detection technologies because they do not require electronic components, resulting in systems and devices that change color upon irradiation. However, their implementation in wearable technology has lightweight, compliance, and durability (especially under mechanical stress) requirements that are limited by the materials’ properties. Here, a self-healing photochromic elastomer composite (photoPUSH) consisting of phosphomolybdic acid (PMA) in a self-healing polyurethane dynamic network with reversible disulfide bonds (PUSH) is presented. The unique properties of the dynamic polymer matrix enable multiple complementary functions in the UV-sensing composite: i) photochromism via electron donor groups without requiring additional dopants, ii) stretchability and durability via elastomeric properties, iii) healing of extreme mechanical damage via dynamic bonds, and iv) multimaterial integration via adhesive properties. PhotoPUSH composites exhibit excellent durability, tunable sensing range, and no loss of performance under mechanical stress and severe damage, as well as in underwater environments (waterproof). Leveraging these properties, soft, portable, multimaterial photoPUSH-based UV-sensing devices are developed for applications in environmental monitoring, packaging, and healthcare wearable technology (including skin-mounted, textile-mounted, and wristband devices) in challenging environments and tunable to different skin types.  相似文献   

9.
Multifunctional films with integrated temperature adjustment, electromagnetic interference (EMI) shielding, and thermal camouflage are remarkably desirable for wearable products. Herein, a novel Janus-type multifunctional ultra-flexible film is fabricated via continuous electrospinning followed by spraying. Interestingly, in the polyvinyl alcohol (PVA)/phase change capsules (PCC) layer (P1), the PCC is strung on PVA fibers to form a stable “candied haws stick” structure that obviates slipping or falling off. The film with sufficient melting enthalpy (141.4 J g−1) guarantees its thermoregulation capability. Simultaneously, its high mid-IR emissivity (90.15%) endows the film with radiative cooling properties (reducing temperature by 10.13 °C). Mechanical strength is significantly improved by superimposing a polylactic acid (PLA) layer (P2) on its surface. By spraying a thin MXene layer on the PLA surface of P2P1 film, the obtained (MXene/P2P1) MP2P1 film is endowed with satisfactory low-voltage heating, photo-thermal and superior thermal camouflage performance, achieving all-season thermal comfort. Impressively, the flexible MP2P1 film achieves enhanced EMI shielding effect from 50.3 to 87.8 dB through a simple origami process, which simplifies the manufacturing process of high-performance EMI shielding materials. In brief, the multifunctional Janus-type MP2P1 film is an attractive candidate for future wearable products with personalized thermal management and anti-electromagnetic radiation.  相似文献   

10.
Among the extensive development of wearable electronics, which can be implanted onto bodies or embedded in clothes, textile-based devices have gained significant attention. For daily basis applications, wearable energy storage devices are required to be stable under harsh environmental conditions and different deformational conditions. In this study, a textile-based stretchable supercapacitor with high electrochemical performance, mechanical stability, and temperature tolerance over a wide temperature range is reported. It exhibits high areal capacitances of 28.0, 30.4, and 30.6 mF cm−2 at −30, 25, and 80 °C, respectively, while the capacitance remains stable over three repeated cycles of cooling and heating from −30 to 80 °C. The supercapacitor is stable under stretching up to 50% and 1000 repetitive cycles of stretching. A temperature sensor and an liquid-crystal display are simultaneously driven at temperatures between −20 and 80 °C by the supercapacitors. The supercapacitors are woven into a nylon glove power a micro-light-emitting diode stably regardless of the bending of the index finger. Furthermore, the encapsulated supercapacitors retain the capacitance during being immersed in water for a few days. This study demonstrates the potential application of the fabricated supercapacitor as a wearable energy storage device that works under extreme temperature variations, high humidity, and body movements.  相似文献   

11.
12.
Flexible and wearable sensors are highly desired for health monitoring, agriculture, sport, and indoor positioning systems applications. However, the currently developed wireless wearable sensors, which are communicated through radio signals, can only provide limited positioning accuracy and are often ineffective in underwater conditions. In this paper, a wireless platform based on flexible piezoelectric acoustics is developed with multiple functions of sensing, communication, and positioning. Under a high frequency (≈13 MHz) stimulation, Lamb waves are generated for respiratory monitoring. Whereas under low-frequency stimulation (≈20 kHz), this device is agitated as a vibrating membrane, which can be implemented for communication and positioning applications. Indoor communication is demonstrated within 2.8 m at 200 bps or 4.2 m at 25 bps. In combination with the sensing function, real-time respiratory monitoring and wireless communication are achieved simultaneously. The distance measurement is achieved based on the phase differences of transmitted and received acoustic signals within a range of 100 cm, with a maximum error of 3 cm. This study offers new insights into the communication and positioning applications using flexible acoustic wave devices, which are promising for wireless and wearable sensor networks.  相似文献   

13.
14.
Cardiovascular disease is the leading cause of death and has dramatically increased in recent years. Continuous cardiac monitoring is particularly important for early diagnosis and prevention, and flexible and stretchable electronic devices have emerged as effective tools for this purpose. Their thin, soft, and deformable features allow intimate and long‐term integration with biotissues, which enables continuous, high‐fidelity, and sometimes large‐area cardiac monitoring on the skin and/or heart surface. In addition to monitoring, intimate contact is also crucial for high‐precision therapies. Combined with tissue engineering, soft bioelectronics have also demonstrated the capability to repair damaged cardiac tissues. This review highlights the recent advances in wearable and implantable devices based on flexible and stretchable electronics for cardiovascular monitoring and therapy. First, wearable/implantable soft bioelectronics for cardiovascular monitoring (e.g., the electrocardiogram, blood pressure, and oxygen saturation level) are reviewed. Then, advances in cardiovascular therapy based on soft bioelectronics (e.g., mesh pacing, ablation, robotic sleeves, and electronic stents) are discussed. Finally, device‐assisted tissue engineering therapy (e.g., functional electronic scaffolds and in vitro cardiac platforms) is discussed.  相似文献   

15.
In the emerging Internet of Things, stretchable antennas can facilitate wireless communication between wearable and mobile electronic devices around the body. The proliferation of wireless devices transmitting near the human body also raises interference and safety concerns that demand stretchable materials capable of shielding electromagnetic interference (EMI). Here, an ultrastretchable conductor is fabricated by depositing a crumple‐textured coating composed of 2D Ti3C2Tx nanosheets (MXene) and single‐walled carbon nanotubes (SWNTs) onto latex, which can be fashioned into high‐performance wearable antennas and EMI shields. The resulting MXene‐SWNT (S‐MXene)/latex devices are able to sustain up to an 800% areal strain and exhibit strain‐insensitive resistance profiles during a 500‐cycle fatigue test. A single layer of stretchable S‐MXene conductors demonstrate a strain‐invariant EMI shielding performance of ≈30 dB up to 800% areal strain, and the shielding performance is further improved to ≈47 and ≈52 dB by stacking 5 and 10 layers of S‐MXene conductors, respectively. Additionally, a stretchable S‐MXene dipole antenna is fabricated, which can be uniaxially stretched to 150% with unaffected reflected power <0.1%. By integrating S‐MXene EMI shields with stretchable S‐MXene antennas, a wearable wireless system is finally demonstrated that provides mechanically stable wireless transmission while attenuating EM absorption by the human body.  相似文献   

16.
The integration of nanomaterials with high conductivity into stretchable polymer fibers can achieve novel functionalities such as sensing physical deformations. With a metallic conductivity that exceeds other solution‐processed nanomaterials, 2D titanium carbide MXene is an attractive material to produce conducting and stretchable fibers. Here, a scalable wet‐spinning technique is used to produce Ti3C2Tx MXene/polyurethane (PU) composite fibers that show both conductivity and high stretchability. The conductivity at a very low percolation threshold of ≈1 wt% is demonstrated, which is lower than the previously reported values for MXene‐based polymer composites. When used as a strain sensor, the MXene/PU composite fibers show a high gauge factor of ≈12900 (≈238 at 50% strain) and a large sensing strain of ≈152%. The cyclic strain sensing performance is further improved by producing fibers with MXene/PU sheath and pure PU core using a coaxial wet‐spinning process. Using a commercial‐scale knitting machine, MXene/PU fibers are knitted into a one‐piece elbow sleeve, which can track various movements of the wearer's elbow. This study establishes fundamental insights into the behavior of MXene in elastomeric composites and presents strategies to achieve MXene‐based fibers and textiles with strain sensing properties suitable for applications in health, sports, and entertainment.  相似文献   

17.
2D MXene materials are of considerable interest for future energy storage. A MXene film could be used as an effective flexible supercapacitor electrode due to its flexibility and, more importantly, its high specific capacitance. However, although it has excellent electronic conductivity, sluggish ionic kinetics within the MXene film becomes a fundamental limitation to the electrochemical performance. To compensate for the relative deficiency, MXene films are frequently reduced to several micrometer dimensions with low mass loading (<1 mg cm?2), to the point of detriment of areal performance and commercial value. Herein, for the first time, the design of a 3D porous MXene/bacterial cellulose (BC) self‐supporting film is reported for ultrahigh capacitance performance (416 F g?1, 2084 mF cm?2) with outstanding mechanical properties and high flexibility, even when the MXene loading reaches 5 mg cm?2. The highly interconnected MXene/BC network enables both excellent electron and ion transport channel. Additionally, a maximum energy density of 252 µWh cm?2 is achieved in an asymmetric supercapacitor, higher than that of all ever‐reported MXene‐based supercapacitors. This work exploits a simple route for assembling 2D MXene materials into 3D porous films as state‐of‐the‐art electrodes for high performance energy storage devices.  相似文献   

18.
Although flexible and multifunctional textiles are promising for wearable electronics and portable device applications, the main issue is to endow textiles with multifunctionalities while maintaining their innate flexible and porous features. Herein, a vacuum‐assisted layer‐by‐layer assembly technique is demonstrated to conformally deposit electrically conductive substances on textiles for developing multifunctional and flexible textiles with superb electromagnetic interference (EMI) shielding performances, superhydrophobicity, and highly sensitive humidity response. The formed leaf‐like nanostructure is composed of silver nanowires (AgNWs) as the highly conductive skeleton (vein) and transition metal carbide/carbonitride (MXene) nanosheets as the lamina. The presence of MXene protects AgNWs from oxidation and enhances the combination of AgNWs with the fabric substrate, and the transformation of its functional groups leads to self‐derived hydrophobicity. The flexible and multifunctional textile exhibits a low sheet resistance of 0.8 Ω sq?1, outstanding EMI shielding efficiency of 54 dB in the X‐band at a small thickness of 120 µm, and highly sensitive humidity responses, while retaining its satisfactory porosity and permeability. The self‐derived hydrophobicity with a large contact angle of >140° is achieved by aging the hydrophilic MXene coated silk. The wearable multifunctional textiles are highly promising for applications in intelligent garments, humidity sensors, actuators, and EMI shielding.  相似文献   

19.
随着谷歌、苹果、三星以及微软等科技巨头相继推出可穿戴设备,该领域正成为研发热点,作为未来最具发展潜力的产业之一,可穿戴设备的相关专利布局早已展开.基于在中国申请的专利文献样本数据,针对可穿戴设备领域的特点、历年的专利申请量、应用领域及技术组成、主要专利申请人等方面对可穿戴设备领域中国专利申请状况进行了分析研究,希望对国内相关企业的技术发展起到一定的作用.  相似文献   

20.
Mechanically robust and electrically conductive organohydrogels/hydrogels are increasingly required in flexible electronic devices, but it remains a challenge to achieve organohydrogels/hydrogels with integrated high performances. Herein, inspired by the geometric deformability and robustness of fishing nets, multiscale ionic organohydrogels with outstanding isotropic mechanical robustness are developed. The organohydrogels are prepared by introducing polyacrylamide (PAM) hydrogel, Zn2+ and a binary solvent of glycerol-water into a crosslinked fibrous mat which is electrospun from poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA). Because of the unique structure, the resultant organohydrogels, being mentioned as PAA-PVA/PAM/Zn2+ organohydrogels, exhibit outstanding tensile strength (9.45 MPa), high stretchability, excellent anti-fatigue property, skin-like mechanical behaviors and ionic conductivity. Importantly, the organohydrogels are promising in flexible electronic devices capable of operating properly over a wide temperature range and under harsh mechanical conditions, such as mechanical-electrical signal transducing materials in flexible mechanosensors and robust electrolytes in zinc ion hybrid supercapacitors. Not only the multiscale design strategy will provide a clue to improve the mechanical properties of soft materials, but also the organohydrogels offer promising materials for future flexible electronic devices.  相似文献   

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