The growing interest in flexible devices has emerged as a global trend due to their advantages in flexibility, lightweight structure, and wearability, addressing the limitations of traditional devices. While wearable airflow sensors have been previously reported, the development of flexible fabric-based airflow sensors capable of functioning in environments with open flames—critical for fire rescue operations—has yet to be explored, largely due to the poor fire resistance of conventional fabrics. In this work, we first present a flexible, wearable, and multifunctional airflow sensor with excellent fire-resistant properties, fabricated through a simple direct laser writing process. This sensor maintains airflow detection capabilities even in the presence of open flames. Typically, the fabrication of fabric-based sensors involves complex procedures such as carbon materials doping or vapor-phase deposition, leading to lengthy preparation cycles and high costs. Furthermore, fabric-based devices are inherently prone to flammability. To address these challenges, we introduce twice-vertical laser-induced graphene (TVLIG) as a sensitive and reliable component for fire-resistant airflow sensors. The resulting TVLIG/Kevlar fabric can be integrated into various garments, particularly protective suits, to form sensitive and fire-resistant airflow sensors capable of detecting airflow velocity and direction in both two-dimensional (2D) and three-dimensional (3D) spaces during fire incidents. Additionally, the TVLIG patterns can be expanded to multifunctional platforms, such as glucose detection for injured individuals, offering further applications in rescue operations. This functional expansion reduces the burden on rescue personnel and streamlines device preparation. With its outstanding sensing capabilities, fire resistance, and expandability, the developed flexible airflow sensor shows great potential for various real-world rescue scenarios, promising advancements in wearable sensing technology for rescue engineering.

Injectability empowers conductive hydrogels to transcend traditional limitations, unlocking a realm of possibilities for innovative medical, wearable, and therapeutic applications that can significantly enhance patient care and quality of life. Here, we report an injectable, self-healable, and reusable hydrogel obtained by mixing the concentrated poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) suspension (~ 2 wt.% solid content), polyvinyl alcohol (PVA), and borax. Leveraging the presence of reversible borax/hydroxyl bonds and multiple hydrogen bonds, this PEDOT:PSS/PVA hydrogel exhibits notable shear-thinning behavior and self-healing capabilities, enabling it to be injected as a gel fiber from a syringe. As-prepared injectable hydrogel also demonstrates an ultra-low modulus (~ 2.5 MPa), reduced on-skin impedance (~ 45% of commercial electrodes), and high signal-to-noise ratio (SNR) (~ 15–22 dB) in recording of electrocardiography (ECG), electromyography (EMG), and electroencephalogram (EEG) signals. Furthermore, the injectable hydrogels can be remolded and reinjected as the reusable electrodes, maintaining nearly identical electrophysiological recording capabilities and brain–computer interface (BCI) performance compared to commercial wet electrodes. With their straightforward fabrication, excellent material properties and electronic performance, ease of cleaning, and remarkable reusability, our injectable PEDOT:PSS/PVA hydrogels hold promise for advancements in BCI based electronics and wearable bioelectronics.

The weak van der Waals gap endows two dimensional transition metal dichalcogenides (2D TMDs) with the potential to realize guest intercalation and host exfoliation. Intriguingly, the liquid intercalation and exfoliation is a facile, low-cost, versatile and scalable strategy to modulate the structure and physiochemical property of TMDs via introducing foreign species into interlayer. In this review, firstly, we briefly introduce the resultant hybrid superlattice and disperse nanosheets with tailored properties fabricated via liquid intercalation and exfoliation. Subsequently, we systematically analyze the intercalation phenomenon and limitations of various intercalants in chemical or electrochemical methods. Afterwards, we intensely discuss diverse functionalities of resultant materials, focusing on their potential applications in energy conversion, energy storage, water purification, electronics, thermoelectrics and superconductor. Finally, we highlight the challenges and outlooks for precise and mass production of 2D TMDs-based materials via liquid intercalation and exfoliation. This review enriches the overview of liquid intercalation and exfoliation strategy, and paves the path for relevant high-performance devices.