Thermally responsive optical materials attract wide applications in information encryption, smart sensors, and intelligent interfaces. However, simultaneously achieving optical switching and multimodal responsiveness with long-term stability remains a challenge. Herein, we develop a thermochromic wood veneer (TWV) that integrates characteristics of color-transparency switching with multimodal thermal activation. This is achieved by incorporating thermochromic microcapsules into a porous wood scaffold and inducing interactions between PVA and cellulose molecules. The resulting TWV exhibits a response temperature about 31 °C in ambient conditions, favorable cyclic stability over 500 thermal cycles, and superior tolerant temperature (-196 °C to 100 °C). Moreover, TWV demonstrates multicolor-transparency switching and diverse thermal activation modalities, including bulk heating, heat transfer printing, and lithography printing. Leveraging the advancement of wood nanotechnology, this work establishes an insight into developing optical and thermal dynamic-response devices from natural resources for advanced applications, such as heat transfer/lithography printing, information encryption/decryption, and smart sensors and tags.

Water transfer printing is a promising method for fabricating large-area organic photovoltaic (OPV) devices. However, the films formed on the water surface (liquid) differ from those formed on glass or plastic substrates (solid). Specifically, the films on the water surface exhibit higher sensitivity to interior stress due to the lack of constrains from bottom substrates. In this work, we report that interior stress drives the formation of wrinkling in the films due to generated capillary force during drying process. This wrinkling makes the subsequent film transfer process challenging, and the resulting devices often exhibit poor performance. To address this issue, drying-induced stress was mitigated from two aspects: reducing film thickness, and adding liquid additive (1,8-diiodooctane) to delay its drying. Therefore, uniform, flat, and smooth films on the water surface were obtained on water surface and then transferred onto target substrates for fabricating OPV device. OPV devices based on the water transfer printed film achieved a power conversion efficiency (PCE) of 17.23%. Large-area flexible OPV modules (70 cm2) fabricated via this method were successfully fabricated and delivered a PCE of 13.84%.

Reducing debris in laser transfer printing utilizing a TiO nanofilm for high-quality additive manufacturing of microscale copper structures

Metal microstructures are fundamental components in electronic and optoelectronic devices. However, traditional energetic ion bombardment deposition techniques often introduce interface defects, strain, disorder, diffusion, and thermal or chemical incompatibility-particularly when integrating metals with two-dimensional semiconductors or unconventional substrates. Consequently, transfer printing techniques have emerged as alternatives. Nevertheless, existing methods typically rely on polycrystalline metals with inferior optoelectronic properties, leading to high optical losses and contact resistance. Here, we present a method for the large-area transfer of electrodeposited, atomically smooth epitaxial gold (Epi-Au) microstructures, including arrays, grids, and dendritic structure films. This approach leverages ultrapure water to induce spontaneous delamination of intact Epi-Au microstructures. Optical and electrical characterizations of the transferred architectures confirm the process reliability. Notably, the transferred 25 nm-thick Epi-Au grid on glass delivers an average electromagnetic interference shielding efficiency of 30.9 dB across the Ku-band (12-18 GHz)-rivalling metals hundreds of nanometers thick-confirming the transferred Epi-Au grids exhibit excellent electrical conductivity. Furthermore, a transferred 6 nm-thick monolithic Epi-Au dendritic structure on a flexible PDMS substrate maintains structural integrity without branch loss and exhibits 70%-80% transmittance across the 400-900 nm wavelength range. These results validate the high fidelity of our transfer method and demonstrate the significant potential of high-quality Epi-Au microstructures for advanced optoelectronic applications.

Transparent conducting electrodes (TCEs) are essential for high-performance organic light-emitting diodes (OLEDs), particularly in transparent and flexible device architectures. Conventional TCEs such as indium tin oxide (ITO) suffer from mechanical brittleness and limited material availability, and often require sputtering processes that can damage underlying organic layers. In response, various alternatives including conductive polymers and nanomaterials or structure-based approaches of metallic films have been explored. However, many of these approaches still face limitations such as low conductivity, poor interfacial contact, or solvent compatibility issues that may degrade device performance. To overcome these challenges, we present a novel direct patterning strategy for top transparent metal mesh electrodes using the metal desorption behavior of solution-processed poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and a transfer printing method. By thermally evaporating silver onto patterned PVDF-HFP layers, we successfully fabricated metal mesh electrodes with high optical transmittance, low sheet resistance, and a maximum figure of merit exceeding 104 using the ratio of electrical conductivity to optical conductivity, which is among the highest reported for sub-micrometer transparent electrodes. This method does not require any lamination, or immersion in solvents or electrolytes, enabling direct integration onto sensitive organic layers. With improved transparency, the metal mesh electrodes were able to be applied as the top cathodes of OLEDs exhibiting comparable electroluminescence characteristics to those with conventional electrodes.

CRISPR-Cas12a moleculardiagnostics offer high sensitivity andspecificity for pathogen detection, yet their translation to point-of-care(POC) settings is often hindered by complex reagent handling, precisethermal requirements, and reliance on bulky laboratory equipment.In this study, we present an integrated opto-thermal paperfluidicplatform engineered for the autonomous, single-step CRISPR-Cas12adetection of Mycobacterium tuberculosis (MTB). The platform’s architecture was optimized by comparinglaser and thermal transfer printing, identifying the latter as thesuperior method for creating robust, leak-proof hydrophobic barrierswhile preserving the structural integrity of the cellulose substrate.To achieve autonomous operation, we developed a hybrid mathematicalmodelincorporating boundary resistance and thermal evaporationtodesign an “intrinsic timer” that aligns capillary flowfront progression with the 15 min CRISPR reaction kinetics. Thermalregulation and signal readout are managed by a custom-engineered,3D-printed hardware module that provides closed-loop 39 °C incubationand high-contrast fluorescence imaging. By utilizing a red-shiftedROX–quencher reporter probe to overcome paper autofluorescenceand sucrose-based lyoprotection for reagent stabilization, the platformachieved a limit of detection of 0.0335 ng/μL with prestoredreagents. Our integrated detection system requires only a single sample-loadingstep and provides results in 15 min, offering a practical, low-costsolution for decentralized tuberculosis surveillance in resource-limitedenvironments.

Prolonged exposure to electronic devices exacerbates neck health issues in modern populations. To address this challenge, we develop a flexible strain sensor based on crack-extension patterned laser-induced graphene (PLIG), designed for high-precision neck posture recognition. Laser-Induced Graphene (LIG), fabricated on a polyimide substrate, was subsequently transferred to a stretchable PDMS substrate, forming the piezoresistive strain sensor with high sensitivity. The successful transfer of Laser-Induced Graphene (LIG) from a polyimide film to a flexible polydimethylsiloxane (PDMS) substrate via a transfer printing method enabled the fabrication of the highly sensitive piezoresistive strain sensor. Through optimized laser processing and patterned structural design, the sensor achieves exceptional performance including a maximum gauge factor of 204.90, rapid response time (113 ms), and robust cycling stability (>5000 cycles). Integrated into an intelligent monitoring system, multichannel LIG signals processed via machine learning algorithms enable recognition of common neck postures with 99.45% accuracy. Further applications in human motion tracking and wireless manipulator control demonstrate the sensor's versatility in wearable electronics, human-machine interfaces, and telemedicine. This work delivers a scalable technical strategy for personalized health management and ergonomic intervention.

ABSTRACT Liquid phases represent the softest class of materials and therefore offer unique characteristics for damage‐free transfer printing of ultrathin semiconductor nanomembranes for flexible and stretchable electronics. Existing liquid‐assisted approaches, particularly those based on liquid metals, however, face several limitations, including the need for a detachable membrane on a donor substrate, potential residual contamination, and complex thermal or laser‐assisted release processes. We present here a preload‐free, droplet‐based transfer‐printing strategy that combines rapid laser patterning with digital microfluidics to enable cleanroom‐free collection, transport, and assembly of 2D nanomembranes onto planar and curved substrates. The implementation of liquid surface tension and droplet actuation enabled by embedded ferromagnetic microbeads provides intrinsic self‐balancing on the droplet apex, self‐alignment with the collecting substrate's footprint, and precise positioning of membranes with intimate conformal contact to 3D surfaces. Through digital microfluidic manipulation, mobile droplets carrying functional membranes can search for, engage, and interface with targeted 3D biological structures, opening a new paradigm of active, reconfigurable sensors. Demonstrations across a range of device classes, including robotics sensors, optically tunable microprisms, and soft electrodes for heart tissues, establish digital droplet‐assisted transfer as a versatile, contamination‐free strategy for integration of heterogeneous materials into flexible, 3D conformal bio‐integrated electronics systems.

Stretchable tactile sensors are essential for robotic skin; however, conventional planar integration methods struggle to accommodate complex geometries, thereby limiting advanced sensing applications. Existing fabrication approaches (e.g., transfer printing) also face scalability challenges due to their reliance on preassembled planar structures. Inspired by biological systems, we propose a novel 3D fabrication strategy that integrates 3D printing, material innovation, and laser direct writing to directly construct stretchable tactile sensor arrays on 3D substrates, enabling seamless multilayer interconnections. Mimicking the 3D folded epidermis of crocodile skin, the proposed biomimetic structure exhibits performance advantages beyond those of human skin. The proof-of-concept sensor arrays demonstrate high responsiveness, with an amplitude response time of less than 0.5ms and a maximum operating frequency of 473.33Hz, along with a frequency resolution of 0.35Hz and an angular resolution of 1°. Notably, 900 sensors were integrated onto a sub-meter-scale film, achieving 100% accuracy in complex pattern recognition tasks via deep learning. This approach enables a transition from 2D to scalable 3D fabrication and provides a versatile platform for next-generation robotic bionic skin and intelligent sensing systems.

The core functionalities of frequency-selective metasurfaces are primarily determined by the geometric shape structures fabricated on their surfaces. Transfer printing technology offers notable advantages in high-efficiency manufacturing and conformal capabilities; however, it struggles to meet the high geometric fidelity requirements of frequency-selective metasurfaces on substrates with varying curvatures. Herein, the authors propose a hyperelastic conformal transfer printing (HCTP) method that regulates the geometric shapes of electromagnetic structures on curved surfaces by means of a shape-preserving mapping algorithm, which is established during the process of transferring planar structures onto surfaces with different Gaussian curvatures under a deformation rate of the hyperelastic stamp exceeding 50%. Spherical bandpass frequency-selective metasurfaces with positive Gaussian curvature and cylindrical bandpass frequency-selective metasurfaces with zero Gaussian curvature are successfully fabricated using HCTP. The manufacturing efficiency of this approach is increased by more than 10 times compared with direct writing methods such as inkjet printing. The geometric shape deviation rate of the frequency-selective metasurface patterns is less than 2%, resulting in a center frequency deviation rate of less than 2%, satisfying the device's performance specifications. Furthermore, the transmittance of electromagnetic waves at the center frequency exceeds 95%.

Laser processing has emerged as a critical enabling technology in the manufacturing of high-efficiency crystalline silicon (c-Si) solar cells. This review systematically examines the fundamental principles and applications of laser technology within the photovoltaic industry. It begins by analyzing the critical influence of laser parameters on the laser-material interaction mechanisms, which ultimately determine the processing quality and the extent of thermal damage. A concise historical overview traces the evolution of laser applications from early laboratory research to later large-scale production of crystalline silicon solar cells. The core of the review is dedicated to a detailed discussion of specific application domains: the utilization of laser thermal effects for doping, oxidation, and crystallization; laser patterning for creating selective emitters, opening passivation layers, and defining intricate structures; and the revolutionary role of lasers in advanced metallization techniques, notably laser pattern transfer printing and laser-assisted sintering. Finally, the review outlines future development trends, highlighting the potential of ultrafast lasers, their integration with novel tandem cell concepts, and the rise of smart, multi-functional stations to push the efficiency and cost-effectiveness of c-Si solar cells.

ABSTRACT Counterfeiting remains a persistent challenge, as existing identification technologies struggle to simultaneously achieve large‐scale deployability and intrinsic security. Macroscopic labels are straightforward to fabricate and read but are vulnerable to duplication, whereas microscopic physically unclonable functions (PUFs) offer high security at the expense of fabrication complexity and verification cost. Here, we propose a wrinkle‐assisted fluorescent hierarchical PUF strategy that integrates controllable replication with nanoscale randomness through transfer printing of self‐assembled quantum dot (QD) nano‐meshes via a surface‐engineered PDMS wrinkled stamp. Random wrinkles with rigid and hydrophilic surface shells are initially generated on PDMS via UVO‐induced bilayer buckling and subsequently subjected to post‐wrinkle surface engineering to restore a soft and low‐surface‐energy stamp, which is essential for high‐quality and durable hierarchical PUF patterns. The reproducibly transferred micro‐fingerprint patterns can be conveniently recorded using portable imaging devices for rapid verification; QD‐assembled nano‐meshes within the wrinkle ridges maintain intrinsically stochastic features arising from interfacial self‐assembly and wrinkle‐assisted transfer, and cannot be deterministically reproduced. When combined with deep learning and feature‐based comparison, this architecture supports accurate and real‐time identification with incremental scalability. This work offers a promising PUF architecture to combine scalable replication and intrinsic security in the anti‐counterfeiting field.

Abstract As devices scale down, the silicon substrate fails to dissipate heat, leading to thermally induced performance degradation. Diamond, with ultrahigh thermal conductivity and wide bandgap, is considered a competitive substrate material for high power density application. The integration of high-quality silicon films onto diamond substrates poses a significant challenge. In this work, a 5 × 5 mm² silicon film was bonded onto diamond using transfer-printing combined with deep silicon etching. The fabricated silicon-on-diamond (SOD) material exhibits low residual stress and a smooth surface (Ra = 0.35 nm). The thermal boundary resistance of the SOD material has been measured at 9.45 m²·K/GW. The temperature rise in the SOD material is 20 ℃ at 150 W/mm², five times lower than the SOI counterpart. The SOD material features outstanding heat dissipation capability, making it promising for high-power-density applications.

Full-colour ultrahigh-resolution quantum dot light-emitting diodes (URQLEDs) with high efficiency and stability are required for next-generation near-eye displays1-3. However, existing quantum dot (QD) patterning techniques struggle to simultaneously achieve submicrometre pixel sizes, full-colour integration and high device performance. Here we report a dual-action force dynamics (DAFD) strategy using a hard silicon template as a nanoimprinting stamp, combined with integral inverted transfer printing. This approach enables red-green-blue (RGB) full-colour QD pixel arrays with densities in the range 9,072-25,400 pixels per inch (PPI), maintaining high-fidelity pattern replication with a conservative transfer yield >99.9%. The method is compatible with both CdSe/ZnS and perovskite QDs on rigid and flexible substrates. Beyond patterning, we identify and address a previously underappreciated bottleneck in ultrahigh-resolution devices-electric-field non-uniformity arising from pixel microstructures. Matching the dielectric constant of the leakage-current-blocking layer to that of the QDs by means of TiO2 nanoparticle incorporation yields a more uniform electric-field distribution, effectively suppressing edge effects and enhancing both efficiency and operational stability. Red URQLEDs at 12,700 PPI achieved a peak external quantum efficiency (EQE) of 26.1% and an operational lifetime T95@1,000 cd m-2 of 65,190 h. Comparable enhancements in device performance were obtained for green and blue URQLEDs, with EQE improvements of 124% and 119%, respectively. RGB-pixelated white URQLEDs reached a peak EQE of 10.1%. By integrating these URQLEDs with complementary metal-oxide-semiconductor (CMOS) integrated circuits, we demonstrated solution-processed active-matrix URQLED animated displays.

Stretchable organic electrochemical transistors (S-OECTs) are known for their high transconductance, low operating voltage, and excellent mechanical compliance. Despite advancements in molecular design and geometric engineering, achieving both high transconductance and stable performance under a large strain remains a challenge. This study demonstrates high-transconductance intrinsically stretchable vertical OECTs, fabricated via a smooth stretchable bilayer electrode and a stretchable organic semiconductor. The combination of a smooth evaporated Au layer and transfer printing of Ag NWs endows the electrode with sub-nanometer surface roughness and high conductivity under stretching, ensuring the devices with both high transconductance (∼55 mS) and stretchability (100%). Under 100% strain, the devices successfully demonstrate rich synaptic functionalities and achieve a remarkably high paired-pulse facilitation (PPF) index of 319.82%. When configured into a reservoir computing network, the system achieves 91.76% accuracy in handwritten digit recognition under 100% strain, showcasing significant potential for wearable neuromorphic electronics applications.

Abstract Quantum dots (QDs) exhibit excellent optical properties and are highly suitable for displays requiring high luminance and a wide color gamut. The development of high-resolution displays has increased interest in QD patterning techniques, including inkjet printing, transfer printing, and lithography. In this study, we demonstrate the direct fabrication of CdSe QDs within poly(vinylpyrrolidone) (PVP) patterns prepared by the lithography. In conventional lithography, QDs are exposed to electron beams, UV, or extreme UV light, which can induce structural damage. The proposed method enables QD patterning without irradiation-induced damage by synthesizing the QDs in situ after pattern formation. CdSe QDs are selectively and directly formed within the PVP patterns, and their emission wavelengths can be tuned by adjusting the synthesis temperature. The immobilization of CdSe QDs within the PVP patterns is further discussed in terms of coordination between the PVP side groups and QDs.

Quantum dot (QD) light-emitting diodes (QLEDs) with high resolution are ideal candidates for next-generation display technologies. Transfer printing offers a route for precise QD patterning, but scaling QLEDs to the nanoscale often degrades pattern uniformity due to uneven stress distribution in conventional transfer printing methods. Here, we report a soft-contact-assisted transfer printing strategy to reduce stress nonuniformity for the fabrication of ultrahigh-resolution QLEDs with uniformly closed-packed QD patterns via polymer interface engineering. Pixels as small as 200 nm are achieved, with an ultrahigh resolution of up to 42,333 pixels per inch (PPI). The resulting red nano-QLEDs deliver impressive peak external quantum efficiencies (EQEs) of 18.6%. Notably, the high-fidelity transfer minimizes performance trade-offs during scaling, allowing nanometer-scale QLEDs to largely retain the efficiency of their micrometer-scale counterparts. This approach enables high-yield fabrication of high-performance nano-QLED arrays, providing a viable route for next-generation high-density visualization.

Purpose This study aims to address the reliability issue of fatigue fracture in internal metal interconnects of flexible vector hydrophones due to strain concentration when deployed on curved surfaces. The core objective is to propose a full semi-circular arc periodic serpentine interconnect structure and to systematically investigate its bending resistance and acoustic sensing performance. The goal is to fill the research gap on serpentine interconnects in the field of flexible hydrophones and to provide theoretical and technical support for complex curved surface applications. Design/methodology/approach This research used a systematic approach combining theoretical modeling, simulation analysis and process optimization. First, a mechanical model for linear and serpentine interconnects was established to theoretically reveal the low-stress mechanism of the serpentine structure. Second, a finite element model coupling solid mechanics and pressure acoustics was built using COMSOL multiphysics to simulate the stress, characteristic frequency, directivity and bending resistance of the flexible hydrophone and its serpentine interconnects. Furthermore, an innovative microfabrication process was developed, using transfer printing to achieve high-performance integration of single-crystal silicon piezoresistors onto the flexible substrate, with process reliability ensured by a multiindex collaborative judgment method. Finally, the piezoresistive effect of the sensitive unit was validated through quasi-static pressure resistance tests. Findings The research yielded the following key findings: regarding mechanical performance, simulations showed that at a bending radius of 8 mm, the maximum von Mises stress of the serpentine interconnect was 688 MPa, which is 31% lower than that of the linear wire, significantly enhancing the fatigue life. Regarding acoustic performance, the flexible hydrophone achieved a sensitivity of −179.75 dB, an 18.75 dB improvement over traditional hydrophones, exhibited good directivity, and had an effective working frequency band of 20–543 Hz. Regarding process and electrical performance, the optimized transfer printing process increased the yield by 35%. The measured piezoresistive coefficient of the sensitive unit reached 3.53 × 10–10 Pa-1, approximately 4.92 times that of traditional bulk silicon, demonstrating that this structure greatly enhances mechanical reliability while maintaining excellent electrical performance. Originality/value The originality and value of this research are reflected in three aspects: first, it proposes a novel full semi-circular arc periodic serpentine interconnect structure without straight segments, specifically addressing the stress concentration problem in high-curvature surface applications. Second, it constructs a dedicated mechanical model for this serpentine interconnect, clarifying the relationship between its stress and geometric parameters, thus providing clear guidance for design. Third, it systematically introduces the serpentine interconnect into the field of flexible vector hydrophones and solves the process challenges of integrating it with the bionic sensitive structure, filling a research gap in this area. This study provides a valuable solution and design basis for developing highly reliable flexible electronic devices suitable for dynamic bending environments.

Transfer printing of metasurface has emerged as a promising technique for realising ultra-high-resolution displays beyond the limits of conventional patterning methods. Reliable transfer requires precise control of adhesion at the interfaces between the metasurface and transfer mold/transfer substrate. Here, we quantitatively investigate adhesion variations at interfaces without or with metasurface, as well as the effects of transfer printing parameters such as applied pressure and temperature. Four paired transfer molds and transfer substrates were fabricated for simulating actual process conditions, and adhesion forces were measured independently using nanoscratch tests. We find that, compared to the specimen without metasurface, adhesion to transfer mold with metasurface is slightly reduced due to the formation of dimples, while adhesion to the transfer substrate with metasurface is significantly decreased resulting from void formation. Application of 5 bar pressure enhances adhesion at both interfaces. In contrast, increasing the temperature to 90 °C decreases adhesion at the transfer mold due to thermally induced residual stresses whereas the transfer substrate adhesion remains nearly unchanged as APS1 activation and residual stress effects counterbalance. Based on the adhesion difference between paired transfer molds and transfer substrates, the optimal conditions of transfer printing are identified as 5 bar and 90 °C. These results elucidate the mechanisms governing adhesion in transfer printing of metasurface and provide guidelines for optimising transfer printing for next-generation ultra-high-resolution displays.

Thanks to the commercial success of organic light-emitting diodes, organic electronics is now much more than just a niche alternative to traditional electronics. However, other types of devices based on organic semiconductors (OSCs) are still far from market readiness. A key limitation is that, in thin-film form, OSCs exhibit a high level of structural disorder. Of all strategies for growing films of OSCs, those relying on organic epitaxy yield films whose properties most closely resemble those of single crystals. Yet, this comes at a cost: conventional substrates for epitaxial growth are incompatible with practical device integration. To overcome this issue, we introduce a transfer printing method capable of relocating epitaxially grown films of OSCs from their native substrates to target, device-compatible ones. We demonstrate the feasibility of this approach by transferring highly crystalline rubrene films─grown via organic molecular beam epitaxy and characterized by coherently oriented, micrometer-scale domains and single-crystal-like optical response─from amino acid single crystals to technologically relevant substrates. Notably, morphology, optical characteristics, and photoluminescence dynamics of the films are fully retained following transfer.