Lan Liu

Developing sustainable adhesives with simultaneous high adhesive strength and excellent work of debonding remains challenging. Here, strong, ultra-tough, environmentally reliable, and recyclable polyurethane adhesives are reported, utilizing a multiscale engineering approach. The multiscale structure employs a top-down design philosophy to merge the advantages of both thermoplastic and thermosetting systems, integrating multi-level organizations including macroscale dual-length dynamic crosslinked networks, mesoscale initial and fibrillar crystals, nanoscale hard phase domains, and molecular scale weak hydrogen bonds. The multiscale structure exhibits the following features: multi-level organizations and surface-anchored high energy phases significantly enhance the bulk cohesion and interfacial adhesion, respectively. And hydrophobic organizations provide barrier mechanisms, while dynamic crosslinking enables network reconfiguration. As a result, the developed adhesive exhibits both high adhesive strength (21.24 MPa) and ultrahigh work of debonding (35,731 N m ^-1 ), coupled with excellent physical and chemical recyclability and environmental reliability (high humidity, water, organic solvents, acids and alkalis, high and ultralow temperatures, aging). This work highlights how multiscale structure enabled by dual-length crosslinked networks simultaneously optimizes bulk cohesion and interfacial adhesion, offering a perspective for designing strong and tough adhesives.

Thermoreversible adhesives allow for on-demand bonding and debonding on diverse surfaces through thermal stimulation. They have great potential in applications such as temporary fixation, which helps lower product costs and meet the requirements for environmental protection. However, the existing thermoreversible adhesive materials face challenges such as imprecise thermal switching, excessively high detachment temperatures, or poor bonding stability. To address these issues, here, we innovatively introduce temperature-responsive crystalline domains with an appropriate melting temperature (T_m) into the adhesive. These crystalline domains stabilize the adhesive network, thereby enabling it to maintain the high lap shear strength of the adhesive across a wide range. However, above T_m, close to the glass transition temperature (T_g) of the amorphous domains, it causes rapid softening and bonding failure. Therefore, the prepared thermoreversible adhesive simultaneously achieves high lap shear strength (5.38 MPa), reliable bonding stability over the normal operating temperature range (>75% of initial value, 30–70 °C), suitable thermal detachment temperature (∼80 °C, 0.66 MPa), and high environmental reliability. This work provides a feasible strategy for designing precision thermoreversible adhesives, which is conducive to promoting the application of thermoreversible adhesives in scenarios such as temporary fixation.

Interfacial mismatch between soft substrates and rigid components fundamentally limits the reliability of stretchable hybrid electronics (SHEs), especially when attempting to simultaneously achieve high bulk strength and strong interfacial adhesion. Here, we introduce a surface activation strategy based on dynamic phenol‐urethane bond exchange to enable self‐adhesive and conductive stretchable conductors, allowing rigid electronic devices to be directly attached to the substrate in a plug‐and‐play manner. A dynamic bisphenol polyurethane elastomer (BPU) was designed to unify high intrinsic strength with tunable dynamic activity by programming phenol‐urethane bonds, resulting in broadly tunable mechanical properties, with tensile strength ranging from 15 to 50 MPa and elongation from 395% to 757%. After 45 min of ethanol‐vapor activation, the BPU surface achieved a peeling strength of 10.5 N/cm while maintaining high mechanical strength (26.6 MPa). A semi‐embedded conductive network was constructed by thermally induced reorganization of Ag nanowires (Ag NWs), yielding stretchable conductors with low sheet resistance (11 Ω/sq), strong adhesion (7.75 N/cm), and high stretchability (≈270%). The prepared SHEs sustain up to 250% strain and retain stable conductivity after 4000 cycles under 30% strain, demonstrating the effectiveness of surface activation in strengthening soft/hard interfaces.

In pursuit of high‐performance flexible strain sensors, achieving an optimal trade‐off among linearity, sensitivity, and strain sensing range remains a critical challenge. Inspired by the wrinkled‐leaf viburnum, we develop a Janus sensor that replicates its asymmetric structure. It comprises a dense, micro‐wrinkled natural rubber (NR)/graphene (GRs) top layer and a loose NR/carbon nanotubes (CNTs) bottom layer, fabricated via facile layer‐by‐layer filtration and pre‐stretching strategy. This bio‐inspired design enables the sensor with a synergistic sensing mechanism: wrinkle‐guided microcrack ensures highly sensitive linear response at low strains; strain‐phase division maintains signal continuity at medium strains; and parallel conductive circuits provide robustness at high strains. As a result, the sensor achieves an exceptional combination of ultra‐high linearity (R ² > 0.999) and sensitivity (gauge factors, GF > 14) across 0–100% strain, with a wide sensing range (> 400%) and fast response (0.16 s). We demonstrate its practical value in human motion detection, physiological signal monitoring, and an intelligent glove system for gesture recognition and human‐machine interaction, highlighting its promising potential for advanced wearable devices and human‐machine interactive systems.

The development of reliable stretchable hybrid electronics (SHEs) requires the formation of soft/rigid interfaces that simultaneously achieve low electrical impedance, robust mechanical-electrical bonding and high energy dissipation capacity, which remains a critical challenge at present. In this work, an innovative alcohol vapor activation for dynamic covalent polyurethane elastomers was presented to address this problem. Specifically, through competitive intervene in the dynamic exchange of hindered urea bonds, ethanol forms irreversible polar urethane terminals, enabling precise surface polarity tuning and enhanced self-adhesion (peel strength of 2.04 N cm^-1) without compromising bulk mechanical properties. This activated surface facilitates significant improvements including high conductivity (8 Ω sq^-1) through rapid nanofiller embedding; direct integration of rigid components with durable interfaces; exceptional electromechanical stability (resistance change less than 10% during bending, twisting, and stretching). The prepared SHEs demonstrate significant potential for applications in stretchable circuits, wearable control terminals, and healthcare monitoring systems.

Developing epidermal electrodes that possess mechanic softness, tough adhesion, and high conductivity simultaneously is important but still remains challenging. Here, polyvinylpyrrolidone (PVP) is introduced into poly(α‐thioctic acid) (PTA) to in situ generate ion‐clusters both in PTA network and on liquid metal particles (LMPs) surface, enhancing the mechanical strength and toughness of PTA, as well as its interfacial interaction with LMPs. As a result, a poly(TA‐PVP)‐LMPs (noted as PTPL) epidermal electrode is reported with mechanic softness (Young's modulus of 175.86 kPa), tough adhesion (1604 J m ⁻² ), high stretchability (>20 000%), rapid self‐healing, and good biocompatibility. And attributed to the peel sintering of LMPs, the PTPL epidermal electrodes further exhibit high electrical conductivity (26.19 mΩ sq ⁻¹ ) and low skin impedance, providing high signal‐to‐noise ratios (SNR of 28.07 dB) and accuracy in monitoring multiple human electrophysiological signals. This work provides a new strategy for balancing the tough self‐adhesion, softness, and high conductivity of polymer materials in epidermal electrodes fabrication.

Hydrogel‐based electrodes are widely used in electrophysiological monitoring for personal disease prevention and home‐based healthcare. However, limited by the hydrogels’ low toughness, poor adhesion, and weak electrical stability, motion artifacts and device detachments are inevitable after long‐term, continuous electrophysiological monitoring. Herein, novel liquid metal@silk fibroin peptide (LM@SF) core‐shell particles, in which the shell SF not only facilitates the core LM's dispersion but also stabilizes the free radicals, are designed to initiate the in situ formation of hydrogel while simultaneously enhancing its toughness, adhesion, and conductivity. As applied in electrophysiological monitoring, the hydrogel can maintain both a stable physical interface and electrical transmission to the skin, thus promoting the signal acquisition quality obviously even during exercise and long‐term wearing. At last, a portable flexible monitoring patch with small volume (70 × 35 × 2 mm) and light weight (7 g) is developed to achieve continuous electrocardiogram (ECG) monitoring via wireless transmission, demonstrating its high potentials in telemedicine.

Self-healing and self-adhesion capacities are essential for many modern applications such as skin-interfaced electronics for improving longevity and reliability. However, the self-healing efficiency and adhesive toughness of most synthetic polymers are limited to their original network, making reliability under dynamic deformation still challenging. Herein, inspired by the growth of living organisms, a highly stretchable supramolecular elastomer based on thermo-responsive ion clusters and a dynamic polysulfide backbone was developed. Attributed to the synergic growth of ion clusters and dynamic exchange of disulfide bonds, the elastomer exhibited unique healing strengthening (healing efficiency >200%) and thermo-enhanced tough adhesion (interfacial toughness >500 J m⁻²) performances. To prove its practical application in highly reliable skin electronics, we further composited the elastomer with a zwitterion to prepare a highly conductive ionic elastomer and applied it in wearable strain sensing and long-term electrophysiological detection. This work provides a new avenue to realize high reliability in skin interfaced electronics.