Misheng Liang

Flexible multi-gas sensor array has promising applications in wearable monitoring, environmental safety and intelligent sensing systems. In this work, a flexible 2 × 2 multi-gas sensor array based on region-functionalized laser-induced graphene (LIG) was developed for room-temperature gas detection and intelligent identification. MXene, MoS₂, TiO₂ and CuO were selectively introduced into different regions of a polyimide substrate, followed by femtosecond pulsed-laser direct writing to form four functionally differentiated LIG-based sensing units. The porous LIG network simultaneously serves as the conductive pathway, gas-adsorption interface, and sensing electrode, enabling the integration of multiple sensing functions within a single flexible platform. The gas-sensing results show that the array exhibits differential response characteristics toward NH₃, H₂S, acetone, and ethanol. LIG@MXene exhibited a pronounced and repeatable response toward NH₃, whereas LIG@MoS₂, LIG@TiO₂, and LIG@CuO showed preferential responses toward H₂S, acetone, and ethanol, respectively. The distinct response amplitudes and polarities of the four sensing channels provide multidimensional features for gas-condition identification. The device also maintained relatively stable NH₃ sensing performance under mechanical bending, with a response retention of approximately 84.2% at a bending angle of 120°. Based on the multidimensional response signals of the four-channel array, a backpropagation neural network (BPNN) was employed for gas-condition identification. The overall correlation coefficient between the network outputs and the numerically encoded target labels reached 0.99974 for the single-gas dataset and 0.94894 for the mixed-gas dataset. This study provides an effective strategy for integrating region-specific material functionalization, flexible laser fabrication, multi-channel sensing, and intelligent gas identification within a single LIG-based sensing platform.

Recently, advances in human-machine interfaces have raised performance demands on flexible sensors. Achieving fast response, wide detection range, and high sensitivity remains a key challenge in flexible pressure sensor design. Here, we present a novel fully-porous flexible capacitive pressure sensor (FPFCPS) with a sandwich structure, comprising laser-induced Cu-composited graphene (LICuG) electrodes and a polyurethane foam dielectric layer modified with ionic liquid and coated with PVA hydrogel. The hierarchical porosity and conductivity of LICuG enable coupled mechanical interlocking and electronic polarization at the electrode-dielectric interface, improving interfacial contact, compressibility, and capacitive response. The sensor achieves a high sensitivity of 863.17 kPa⁻¹, a wide detection range (10 Pa-500 kPa), and a rapid response time of 5 ms, along with excellent flexibility and long-term stability. Notably, FPFCPS enables rapid tactile feedback and material recognition in dynamic robotic operations, offering high-resolution sensing in complex environments. This work represents the first application of LICuG in electric double-layer capacitance-pressure sensors and establishes a new structural design paradigm based on a fully porous architecture. It provides theoretical insights and practical strategies for advancing material development, mechanistic understanding, and implementation of intelligent sensing systems. In this study, femtosecond-laser-induced Cu-composited graphene (LICuG) was successfully synthesized. By incorporating this novel composite material into an electric double-layer capacitance sensing system, a fully-porous flexible capacitive pressure sensor (FPFCPS) was constructed. Through the synergistic regulation of the sensor's interlayer structural and electrical properties, its overall performance was significantly enhanced. When integrated at key robotic joints, the FPFCPS successfully detected collisions within ~5 ms and was capable of identifying the type of obstacle through tactile contact.

Driven by the rising demand for mechanical adaptability, structural reconfigurability, and multifunctional integration, flexible circuits are gaining increasing importance in advanced electronic systems. They serve as key enablers for next-generation devices owing to their intrinsic mechanical compliance and stable electrical performance. In extreme environments, flexible circuits face severe reliability issues such as dielectric drift, interfacial delamination, crack propagation, and metal electromigration. Nevertheless, their deployment remains indispensable in aerospace systems operating under high temperature and pressure, in biomedical implants exposed to corrosive environments and dynamic loading, and in energy infrastructures subjected to strong acids, alkalis, and severe thermal gradients, since rigid alternatives cannot satisfy the stringent demands for mechanical adaptability and lightweight integration. This duality underscores both the challenges and the necessity of advancing flexible circuit technologies, where material innovations and cross-process strategies are crucial to ensure functionality under harsh conditions. This review provides a comprehensive account of the technological evolution of flexible circuit fabrication. On the materials front, the engineering of multiscale composite conductive networks has proven to significantly enhance interfacial bonding strength and environmental robustness. In terms of fabrication, subtractive manufacturing exhibits mature performance in patterning resolution, thermal effect suppression, and substrate compatibility. Additive manufacturing extends the frontier toward heterogeneous material integration and three-dimensional functional architectures. Meanwhile, conformal manufacturing provides novel paradigms for configurational control and interface modulation. By analyzing the characteristics and strengths of these fabrication strategies, this article further maps the application potential of flexible circuits in sensor arrays, communication modules, bioelectronic systems, and integrated photonics. It emphasizes the need to align process design with performance requirements. Key challenges remain, including reliability under extreme environments, delays in adopting sustainable manufacturing, and limited cross-process integration. Ultimately, the study argues that the future development of flexible circuits hinges on the innovation of functionalized materials, the establishment of sustainable fabrication platforms, and the convergence of hybrid manufacturing pathways. Together, these advances will drive a paradigm shift from passive structural flexibility to active system reconfiguration. Meanwhile, they will expand the scope of flexible electronics toward extreme, green, and reconfigurable application scenarios.

Photoenhanced energy storage devices represent an emerging technology that integrates solar energy harvesting with efficient electrochemical storage. However, achieving seamless and efficient coupling between light utilization and high-performance charge storage within a single, integrated platform remains a major challenge. To address this challenge, this study develops laser-architected MXene-graphene composites that unify high-performance energy storage with photoenhancement. The reduced graphene oxide (rGO) and partially oxidize MXene composite induced by a laser redox process exhibits a hierarchical architecture with outstanding conductivity and surface area. This synergy enables supercapacitors with photoenhanced capacitance, delivering a 228% boost under illumination and record-breaking metrics in capacitance, 2591.75 farads per cubic centimeter (1455.21 farads gram), energy density, 0.518 watt-hours per cubic centimeter (0.345 watt-hours gram), and power density, 320.35 watts per cubic centimeter (180.31 watts gram). Our findings offer a promising route toward integrated, photoenhanced energy systems, advancing the vision of efficient and sustainable power technologies.

Laser-induced graphene (LIG) has become a promising stealth material due to its excellent electromagnetic loss characteristics in the terahertz and microwave bands (2–18 Ghz) and the advantages of low-cost large-scale manufacturing. With the rapid advancement of electromagnetic detection technologies toward multispectral and high-dynamic-range capabilities, there is an increasing demand for LIG-based stealth materials with superior absorption performance. The synergistic design of functional material doping and structural configurations has been identified as a critical approach to achieve high electromagnetic shielding performance in LIG-based composites. This article briefly reviews the developmental progress of LIG-based electromagnetic stealth materials, with a particular emphasis on doping technologies and shielding mechanisms tailored for stealth applications. Furthermore, we propose potential future development pathways for LIG-based stealth materials to facilitate their transition toward broader practical applications.

Flexible electromagnetic metamaterials are a potential candidate for the ideal material for electromagnetic control due to their unique physical properties and structure. Flexible electromagnetic metamaterials can be designed to exhibit specific responses to electromagnetic waves within a particular frequency range. Research shows that flexible electromagnetic metamaterials exhibit significant electromagnetic control characteristics in microwave, terahertz, infrared and other frequency bands. It has a wide range of applications in the fields of electromagnetic wave absorption and stealth, antennas and microwave devices, communication information and other fields. In this review, the currently popular fabrication methods of flexible electromagnetic metamaterials are first summarized, highlighting the electromagnetic modulation capability in different frequency bands. Then, the applications of flexible electromagnetic metamaterials in four aspects, namely electromagnetic stealth, temperature modulation, electromagnetic shielding, and wearable sensors, are elaborated and summarized in detail. In addition, this review also discusses the shortcomings and limitations of flexible electromagnetic metamaterials for electromagnetic control. Finally, the conclusion and perspective of the electromagnetic properties of flexible electromagnetic metamaterials are presented.

This study presents what we believe to be a novel method using a laser-induced heat-shrinkable polymer to leverage the rapid processing capabilities of femtosecond-laser-prepared microstructures and accelerate the fabrication of three-dimensional optical metasurface biochemical sensors. Arrays of micropillar unit structures, each 220 µm in height, were successfully fabricated by modulating laser-induced contraction. These arrays exhibited exceptional performance in fingerprint spectral coupling and biochemical sensing, achieving detection limits of 6 nM for lactose and 8 pg/mL for the SARS-CoV-2 S protein. The metasurface sensors demonstrated high sensitivities and low detection limits, while the simplified manufacturing process further enhanced device performance, highlighting the method’s potential for advanced biochemical sensing applications.

Flexible sensors based on laser‐induced graphene (LIG) are widely used in wearable personal devices, with the morphology and lattice arrangement of LIG the key factors affecting their performance in various applications. In this study, femtosecond‐laser‐induced MXene‐composited graphene ( LIMG ) is used to improve the electrical conductivity of graphene by incorporating MXene, a 2D material with a high concentration of free electrons, into the LIG structure. By combining pump‐probe detection, laser‐induced breakdown spectroscopy (LIBS), and density functional theory (DFT) calculations, the morphogenesis and lattice structuring principles of LIMG is explored, with the results indicating that MXene materials are successfully embedded in the graphene lattice, altering both their morphology and electrical properties. The structural sparsity and electrical conductivity of LIMG composites (up to 3187 S m ⁻¹ ) are significantly enhanced compared to those of LIG. Based on these findings, LIMG has been used in wearable electronics. LIMG electrodes are used to detect uric acid, with a minimum detection limit of 2.48 µM. Additionally, LIMG ‐based pressure and bending sensors have been successfully used to monitor human limb movement and pulse. The direct in situ femtosecond laser patterning synthesis of LIMG has significant implications for developing flexible wearable electronic sensors.