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• A multi-functional CNF-Ag/GO hybrid film with was manufactured by a simple dip-coating method. • Focusing on the development of multifunctional wearable materials, the EMI shielding performance of the millimeter range (26-40 GHz) and antibacterial ability were investigated in detail. • The flexibility and motion detection functions of the hybrid film have also been explored. Strong electromagnetic radiation has seriously threatened human body health due to the rapid development of 5G electronic devices towards millimeter wave. The demand for wearable and antibacterial materials with high-performance electromagnetic protection is very urgent, but still lack reasonable structure design to realize multifunctional structure. Here, a wearable and antibacterial cellulose nanofiber/silver nanowire/graphene oxide (CNF-Ag NWs/GO) hybrid film with a multilayer structure is successfully fabricated by a convenient dip-coating method. Such a multilayer structure is constituted by a flexible CNF substrate, electromagnetic shielding blocks of Ag NWs and encapsulation units of GO. Benefiting from the packaging of GO sheets by the hydrogen bond interaction, a dense Ag NWs conductive network is woven. The resulting film shows extremely low sheet resistance of 0.9 Ω/sq and superior electromagnetic shielding performance of 80 dB in the millimeter wave range (26-40 GHz). Meanwhile, an excellent antibacterial property and a motion monitoring ability with high sensitivity are also acquired. The work realizes a multi-functional integration and provides new insight into the development of wearable electromagnetic protection materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic phase-locked supramolecular elastomers are reported. • A coupling of Hierarchical H-bonds and hydrophobic domains is established. • Outstanding underwater healing efficiencies with high strength are achieved. • Reliable aquatic strain-sensing is demonstrated for underwater iontronic devices. Water-resistant conductive elastomers can endow soft electronic devices with reliable sensing performance for motion monitoring and real-time communication in aquatic environments. Nevertheless, traditional conductive elastomers typically suffer from notable shortcomings in terms of inferior mechanical robustness, weak stability, and self-healing capabilities in wet conditions and even underwater, significantly restricting their practical utility. Drawing inspiration from the optimization of multiphase structure, an ultrarobust underwater healable elastomer is constructed by incorporating biomass-derived long-chain segments with a large number of amide/benzene groups into a hierarchical H-bonding supramolecular network. The locking of multiple dynamic bonds by uniformly distributed hard-phase domains with dense hydrophobic barriers leads to the resultant elastomer gaining remarkably enhanced mechanical properties (stretchability, 2217.2 %; toughness, 272.97 MJ m−3) and outstanding capability to autonomously self-heal even underwater with a high ultimate strength over 10 MPa (aqueous healing for 24 h). Notably, it boasts exceptional healing stability to all types of harsh aqueous environments, such as strong acid/alkali, high temperature, and salty water. The application of the developed elastomer is also demonstrated by creating a multifunctional wearable sensor that can accurately detect and transmit information for a variety of human motions in both atmospheric and aquatic environments. The viable strategy reported herein for designing advanced multifunctional healable materials can be applicable for all-environment flexible iontronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] Eutectogels are emerging as attractive soft conductors for flexible wearable electronics and next-generation human–computer interaction devices owing to their inherent environmental stability and high ionic conductivity. However, it remains a challenge to achieve efficient multifunctional integration of flexible wearable sensors through a convenient and environment-friendly approach. Herein, the eutectogel with excellent mechanical properties, self-healing, environmental tolerance, reversibly fluorescent and high conductivity was prepared via a facile UV-initiated one-step polymerization. Abundant hydrogen bonds and multiple dynamic interactions impart the eutectogel with excellent tensile strength (1.99 MPa), high stretchability (>1500 %), high toughness (20.85 MJ/m3), strong self-adhesion (192 kPa), and autonomously self-healing (>92 %) capabilities. Due to the dynamic photochemical reaction of the anthracene groups, the eutectogel exhibits tunable and reversible fluorescence. The eutectogel-based flexible wearable devices and wireless interaction systems can be used for non-contact information writing and transmission, motion monitoring, wireless communication, and human–computer interaction, which achieves the working modes of digital and visual signals complementing each other as well as efficient multifunctional integration. Therefore, this simple and environment-friendly design concept can provide new ideas for the development of multifunctional integrated portable flexible sensing devices and wireless interactive systems. [ABSTRACT FROM AUTHOR]

• • A serpentine MWCNT-COOH / PEDOT: PSS-based liquid electrode sensor was prepared. • • SLEDSS features dual modes: resistive mode and triboelectric mode. • • SLEDSS boasts excellent operational stability and durability. • • SLEDSS is capable of accurately detecting various limb movements. Flexible and stretchable electrodes are crucial components for wearable electronic devices. Herein, a serpentine liquid electrode based dual-mode skin sensors (SLEDSS) that leverages a highly deformable and serpentine liquid electrode is developed. The functional carboxylated multi-walled carbon nanotubes / Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (MWCNT-COOH / PEDOT: PSS) network structure endows the SLEDSS with a stable linear change in resistance. Additionally, a solid–liquid double electric layer generated between the solid surface and liquid electrode facilitates a higher triboelectric output performance. As a result, the SLEDSS features dual-modal sensing capabilities, including both resistive and triboelectric modes. The flowability of the liquid electrode enables it to fully adapt to different types of deformation, thereby allowing SLEDSS to effectively collect energy in different forms of movement, such as tapping, stretching, bending, twisting, and unpredictable transformations based on practical applications. SLEDSS can maintain its performance even at up to 550.32% strain, displaying a monotonically increasing relationship between the stretchable length and open-circuit voltage. Finally, the SLEDSS is applied as a wearable power source and self-powered sensor for monitoring biomechanical movements, the excellent stretchable performance and ultra-high sensitivity to mechanical stimulation provided by the SLEDSS offer new prospects for self-powered sensors. [ABSTRACT FROM AUTHOR]

• Biodegradable bacterial Polypyrrole strain sensor encapsulated with EcoFlex. • In-situ fermentation shows uniform nanofiller dispersion and 3D conductive networks. • Crack-based strain sensing has a working range of 0.05–90% maximal strain. • ΔR/R 0 readings are consistent under different loading rates and strain ranges. • Strain sensor accurately detects minute pulses, applicable to monitor vital signs. Microbial production of biopolymers are non-standard materials in wearable resistive-strain sensors, despite established and desirable scale-up, rheological, ecological and economical properties. In this study, we report a biodegradable bacterial cellulose (BC) crack-based strain sensor prepared by in-situ fermentation with polypyrrole (PPy) and encapsulation with Ecoflex (EF) for human-interactive sensing. In-situ microbial fermentation method not only optimizes the distribution state of PPy but also constructs the three-dimensional conductive network, which contributing to the formation of crack-based sensing mechanism. The as-prepared BC/Ppy@EF strain sensor exhibits high sensitivity (gauge factor of 3.21–4.86), large strain ranges (up to 90% strain), ultralow strain detection limit (0.05%) and remarkable long-term stability without any distinct decline in sensitivity after a constant applied stretching of 90% for 1000 cycles. The strain sensor accurately detected a full range of body motions, including subtle vital signs like pulse, respiration and vocalizations, and was successfully integrated into textiles for human–computer interactions. Consequently, this study provides empirical value for the bio-fabrication and all-green construction design of wearable devices, as well as the development of human–computer interaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lightweight and stretchable graphene armor for EMI shielding and strain sensing. • Sandwich architecture is designed to enhance EMI shielding performance and strain sensing sensitivity of the graphene armor. • The laminated graphene film is fabricated by laser induction in a single step under an ambient atmosphere. • The sandwich graphene armor exhibits an EMI SE up to 69.8 dB at an ultralow density of 0.228 g/cm3. • The gauge factor of the graphene armor can reach 258 at a strain range up to 100%. Lightweight and stretchable electromagnetic interference (EMI) shielding materials are desirable for wearable electronics. Herein, a graphene armor composed of laminated graphene film (LGF) and hierarchical porous graphene foam (HGF) with film/foam/film sandwich architecture is reported for human EMI shielding and motion monitoring. The LGF with micron-level interlayer spacing (∼2 μm) is fabricated by laser induction in a single step under an ambient atmosphere. Attributed to abundant interfaces and excellent electrical conductivity of 1670 S/m, the LGF exhibits an EMI shielding effectiveness (SE) up to 36.3 dB at a thickness of 19.4 μm. Due to the three-dimensional porous foam structure with the tunability of graphene content, the EMI SE of the HGF can range from 10 to 80 dB. Based on HGF with a graphene content of 27 wt%, the sandwich graphene armor with a thickness of about 2 mm exhibits an EMI SE up to 69.8 dB at an ultralow density of 0.228 g/cm3. Furthermore, the graphene armor possesses excellent mechanical properties as strain sensors that the gauge factor can reach 258 at the strain range up to 100%, thus the graphene armor can be used for motion monitoring while protecting the joints of the human body. The results demonstrate that sandwich architecture can not only enhance the EMI shielding performance of foam materials but also be an effective approach to improving the sensitivity of strain sensors. Therefore, the highly stretchable, conformal, and lightweight sandwich graphene armor is promising for multifunctional applications of EMI shielding and strain sensing. [ABSTRACT FROM AUTHOR]