Zwitterionic dual-network strategy for highly stretchable and transparent ionic conductor

Highly Ionic Conductive, Stretchable, and Tough Ionogel for Flexible Solid-State Supercapacitor

The increasing demand for wearable electronics calls for advanced energy storage solutions that integrate high  electrochemical performances and mechanical robustness. Ionogel is a promising candidate due to its stretchability combined with high ionic conductivity. However, simultaneously optimizing both the electrochemical and mechanical performance of ionogels remains a challenge. This paper reports a tough and highly ion-conductive ionogel through ion impregnation and solvent exchange. The fabricated ionogel consists of double interpenetrating networks of long polymer chains that provide high stretchability. The polymer chains are crosslinked by hydrogen bonds that induce large energy dissipation for enhanced toughness. The resultant ionogel possesses mechanical stretchability of 26, tensile strength of 1.34 MPa, and fracture toughness of 4175 J m-2. Meanwhile, due to the high ion concentrations and ion mobility in the gel, a high ionic conductivity of 3.18 S m-1 at room temperature is achieved. A supercapacitor of this ionogel sandwiched with porous fiber electrodes provides remarkable areal capacitance (615 mF cm-2 at 1 mA cm-2), energy density (341.7 µWh cm-2 at 1 mA cm-2), and power density (20 mW cm-2 at 10 mA cm-2), offering significant advantages in applications where high efficiency, compact size, and rapid energy delivery are crucial, such as flexible and wearable electronics.

Smart and programmed thermo-wetting yarns for scalable and customizable moisture/heat conditioning textiles

Programmable smart textiles with adaptive moisture/heat conditioning (MHC) capabilities are globally being sought to meet the requirements of comfort, energy efficiency, and health protection. However, a universal strategy for fabricating truly scalable and customizable MHC textiles is lacking. In this study, we introduce a scalable in situ grafting approach for the continuous fabrication of two series of smart textile yarns with opposite thermoresponsive wetting behaviors. In particular, the wetting transition temperature can be precisely programmed by adjusting the grafting formula, making the yarns highly customizable. The smart yarns demonstrated excellent mechanical strength, whiteness, weavability, biocompatibility, and washability (with more than 60 home washes), comparable to those of regular textile yarns. They can serve as building blocks independently or in combination to create smart textiles with adaptive sweat wicking and intelligent moisture/heat regulation capabilities. A proposed hybrid textile integrating both the two series of smart yarns can offer dry-contact and cooling/keep-warming effects of approximately 1.6/2.8 °C, respectively, in response to changes in ambient temperature. Our method provides a rich array of design options for nonpowered MHC textiles while maintaining a balance between traditional wearing conventions and large-scale production.

Designing Multimodal Informative Sensing with an Exosome-Mediated Signal Coupling Transduction Strategy Based on a Single-Stimulus Multiresponse Recognition Interface

Given that exosomes released from cancer cells carry various tumor-specific proteins on their surface, they have emerged as a source of biomarkers for cancer diagnosis. However, developing accurate and reliable assays to detect exosomes in the early stages of disease with low abundance and complex systems remains challenging. Here, the prepared PDIG film has the ability to sense multiple signals from a single stimulus, in which the presence of cobalt(II) chloride and deep eutectic solvents (DES) endows PDIG with thermochromic and thermosensitive properties. Concretely, the PDIG served as the recognition interface in series with a bipolar electrode (BPE) that exhibits a highly sensitive color and conductivity response to temperature stimuli triggered by the light-harvesting probe TiO2@CNOs introduced via proximity hybridization assay triggering a rolling circle amplification strategy, resulting in the output of colorimetric, photoacoustic, and electrochemiluminescent signals for the detection of colorectal cancer exosomes. This work is expected to provide a new direction for exploring the multisignal amplification strategy of BPE, broaden the application of BPE in biological analysis, and provide new insights for developing highly information-sensing elements to ensure the multimodal coupling for cancer-specific exosome detection.

Self-Healing, Reconfigurable, Thermal-Switching, Transformative Electronics for Health Monitoring

Soft, deformable electronic devices provide the means to monitor physiological information and health conditions for disease diagnostics. However, their practical utility is limited due to the lack of intrinsical thermal switching for mechanically transformative adaptability and self-healing capability against mechanical damages. Here, the design concepts, materials and physics, manufacturing approaches, and application opportunities of self-healing, reconfigurable, thermal-switching device platforms based on hyperbranched polymers and biphasic liquid metal are reported. The former provides excellent self-healing performance and unique tunable stiffness and adhesion regulated by temperature for the on-skin switch, whereas the latter results in liquid metal circuits with extreme stretchability (>900%) and high conductivity (3.40 × 104  S cm-1 ), as well as simple recycling capability. Triggered by the increased temperature from the skin surface, a multifunctional device platform can conveniently conform and strongly adhere to the hierarchically textured skin surface for non-invasive, continuous, comfortable health monitoring. Additionally, the self-healing and adhesive characteristics allow multiple multifunctional circuit components to assemble and completely wrap on 3D curvilinear surfaces. Together, the design, manufacturing, and proof-of-concept demonstration of the self-healing, transformative, and self-assembled electronics open up new opportunities for robust soft deformable devices, smart robotics, prosthetics, and Internet-of-Things, and human-machine interfaces on irregular surfaces.

Stretchable Ionic Conductors for Soft Electronics

With the rapid development of soft electronics in the era of Internet of Everything (IoE), electrical conductors with stretchability, the indispensable components of soft electronics, have gained new opportunities and also faced increasing challenges. According to the principles of electrical conductivity, stretchable electrical conductors can be divided into electronic conductors and ionic conductors. Different from the stretchable electronic conductors derived from stretchable polymeric matrices integrated with electronically conductive fillers, stretchable ionic conductors are constructed by embedding mobile ions into the crosslinked polymer networks. Therefore, stretchable ionic conductors have received extensive attention and in-depth research in the past decade, thanks to their intrinsic stretchability and electrical conductivity. This review systematically summarizes the achievements on the different categories of stretchable ionic conductors (e.g., hydrogels, ionogels, and liquid-free ion-conductive elastomers), in terms of their design, fabrication, properties, and applications. The advantages and limitations of the different types of stretchable ionic conductors are discussed. Outlooks are also provided to envision the remaining challenges for the further development and practical applications of stretchable ionic conductors. It is expected to arouse inspirations for the design and fabrication of new and high-performance stretchable ionic conductors and advanced soft electronics for the IoE era. This article is protected by copyright. All rights reserved.

Self-adhesive and anti-fatigue cellulose-polyacrylate ionogels prepared by ultraviolet curing used as biopotential electrodes

Conductive hydrogels have been extensively studied because of flexibility and skin-like capability to be used as biopotential electrodes for wearable health monitoring. However, they may suffer from poor mechanical properties and stability problems when used in practical applications caused by water evaporation. Herein, we prepared self-adhesive, transparent, flexible and robust ionic gels that can conformal contact with the skin used as biopotential electrodes for precise health monitoring. Cellulose based iogels were prepared by dissolving cellulose using [Bmim]Cl at 100 °C followed by in situ Ultraviolet light photopolymerization of acrylic acid by adding a mixture of acrylic acid and 2-hydroxy-2-methylpropiophenone. Cellulose/polyacrylic acid-based ionic gels-2 (BCELIG-2) has a Young's modulus of 0.2 MPa, a strain at break of 226 %, a modulus of elasticity of 0.1 MPa, and a toughness of 22.5 MJ m^-3. Fixing the strain at 40 %, the ionic gels can recover to their original length after ten tensile-unloading cycles. They can accurately detect subtle physical motions such as arterial pulsations, which can provide important cardiovascular information.

Synergistically modified WS2@PANI binary nanocomposite-based all-solid-state symmetric supercapacitor with high energy density

WS2@PANI nanocomposite prepared by hydrothermal and physical blending method shows remarkably high specific capacitance and energy density while retaining excellent cyclic stability.