Polydimethylsiloxane (PDMS), renowned for its exceptional stretchability and biocompatibility, has been extensively employed as a flexible substrate for wearable and stretchable electronics. However, the functional failure of 3D-printed PDMS structures caused by insufficient interlayer bonding strength significantly limits their applications. To address this challenge, this study innovatively proposes a manufacturing method for selective PDMS curing based on photothermal conversion, in which polyimide (PI) film is introduced as an intermediate thermally conductive medium to enable selective laser heating and localized curing of highly transparent PDMS. This strategy not only provides structural support for functional layers via laser-selective curing of PDMS but also retains substantial uncured regions to enable covalent crosslinking between adjacent PDMS layers, thereby effectively improving the interlayer bonding strength. Moreover, the laser-cured zones are encapsulated within these uncured portions, further achieving the enhancement of interlayer bonding strength of PDMS-based 3D-printed devices. The results demonstrate that compared with conventional fully curing layer-by-layer printing approaches, the samples prepared by this strategy exhibited cohesive failure during the T-peel test, while pull-off testing demonstrated a minimum 2.36-fold enhancement in interfacial bonding strength, and optical microscopy observations at 20× magnification revealed no delamination at the interfaces. Leveraging this method, a flexible strain sensor with stable performance over 1000 cycles and a microfluidic chip capable of withstanding a flow rate of 1000 μL/min without leakage were successfully fabricated.

The flexible transparent antenna is an innovative type of antenna designed to meet the usage requirements such as high transparency, low profile, and compact size, etc. However, the fabrication of flexible transparent antenna with excellent transmittance and radiation performance has been a challenge that limits the wide application of flexible transparent antennas. Therefore, this paper proposes a method of a flexible transparent antenna using metal mesh embedded in PDMS that integrates electric-field-driven microjet 3D printing and plating. Based on the proposed method, a coplanar waveguide-fed monopole transparent antenna and a frequency selective surface (FSS) is designed for verification. The results show that the fabricated flexible transparent antenna with 83% transmittance obtains a bandwidth of 3.2–4.8 GHz, the peak gain in the operating band is greater than 5 dB, and the in-band radiation efficiency reaches more than 80%, which can be used in 5 G n77,n78 and n79 bands. The fabricated FSS is integrated into the back of the transparent antenna, which reduces the specific absorption rate by 35% and improves the gain of the transparent antenna, which verifies the feasibility of the method. Therefore, the proposed method is expected to have good application prospects in the fabrication of high-performance flexible wearable transparent antennas.

Flexible transparent antennas (FTAs) are widely used in wireless transmission fields, and their technological iterations are accelerating. However, the high losses caused by materials and structures limit the development of FTAs with both high light transmission and high gain, and the rapid iteration rate demands greater process flexibility, which makes it difficult for existing technologies to achieve both demands. Here, we design a novel shell-core structure composite metal mesh (CMM) FTA to achieve extremely low skin depth loss and ohmic loss using skin effect and report a novel hybrid additive manufacturing method based on electric field oriented deposition to achieve efficient and flexible manufacturing of the unique Ag/Cu core-shell structure CMM FTA. The typical sample has a light transmittance of 80% (including substrate) when the sheet resistance is 0.29 Ω·sq ^−1 , and has excellent bending and torsion resistance. The peak gain in the working band is as high as 5.22 dB, and the efficiency is 80%, which is close to the performance of the opaque Cu patch antenna. It also realizes smooth and stable real-time wireless transmission under bending and long-distance conditions. This method addresses the shortcomings of FTAs, namely their high cost, low manufacturing efficiency, and low performance, especially in the rapid iterative development of antennas.

Objective Inconel 718 alloy, renowned for its outstanding high-temperature strength, oxidation resistance, and corrosion resistance, has found extensive applications across aerospace, energy, and other critical sectors. The advent of the additive manufacturing technology, particularly the laser powder bed fusion technology, has opened up novel avenues for the fabrication of Inconel 718 alloy and its composites. Nevertheless, the intricate microstructure of components produced by this technology gives rise to selective dissolution during subsequent electrochemical machining. This phenomenon not only deteriorates the surface quality but also restricts the further expansion of its applications. Methods In this study, laser powder bed fused Inconel 718 alloy and TiB2/Inconel 718 composite are used to innovatively address the surface quality problem faced by traditional electrolytic grinding. The core purpose of this research is to deeply explore the intrinsic relationship between the microscopic properties of materials and the processing technology, so as to optimize the processing quality and expand the application range of materials. Specifically, this research uses X-ray photoelectron spectroscopy (XPS) analysis technology to determine the chemical composition and elemental distribution of the superpassivation films of two materials. Through a detailed analysis of the composition of the superpassivation film, the aim is first to reveal its formation mechanism and the influence on the surface properties of the material during processing, and then to study the parameters of the electrolytic grinding process including different feed rates and rotational speeds and the relationship between the microstructure of materials and the electrolytic grinding surface quality . Scanning electron microscope (SEM) is used to observe the microstructural changes of materials under different process parameters in real time, and the surface quality parameters after electrolytic grinding can be accurately determined in combination with surface roughness measuring instruments and other equipment. Through comprehensive and detailed experimental data collection and analysis, the influence mechanism of microstructure on surface quality under different process conditions is deeply explored. Results and Discussions Compared to Inconel 718 alloy, TiB2/Inconel 718 composite can form a denser superpassivation film during electrolytic machining. The root cause of this phenomenon is that the addition of TiB2 induces the formation of more homogeneous microstructures inside the material. At the microscopic level, the uniformly distributed TiB2 particles act as a "backbone" and provide numerous stable attachment sites for the growth of superpassivation films. These sites make the superpassivation film more uniform in the formation process, and due to its strong interaction with the TiB2 particles, the superpassivation film can be firmly attached to the TiB 2 particles, effectively avoiding being washed away by the electrolyte, thus ensuring the integrity and stability of the superpassivation film and improving the corrosion resistance of the material. Both materials are composed of Ni(OH)2, Fe(OOH), Fe3O4, Cr(OH)3, Cr2O3, TiO 2, MoO2, Nb2O5, and other compounds. It is worth noting that the added TiB 2 does not participate in electrochemical dissolution throughout the electrochemical processing process, and mainly plays a role in enhancing the microstructural stability and promoting the formation of superpassivation films in the material. When it comes to the study of the effect of process parameters on surface quality, both Inconel 718 alloy and TiB 2 /Inconel 718 composite are available at a feed rate of 1.33 mm/s and a rotational speed of 1000 r/min, the surface quality is at its best, the surface is extremely flat, and there are no pits. At the same time, the gouge phenomenon caused by stray corrosion has been significantly improved, and the gouge amount has been greatly reduced. Conclusions Compared with Inconel 718 alloy, the nano-TiB2 particles in the microstructure of TiB2/Inconel 718 composite are diffusely distributed in the dendrite, which forms a denser superpassivation film in electrolytic machining, and the optimal parameters in electrolytic grinding are 1.33 mm/s and 1000 r/min, in which the volumetric electrochemical equivalent of Inconel 718 alloy is 1.727 mm3/(A center dot min), and the volumetric electrochemical equivalent of TiB2/ Inconel 718 composite is 1.796 mm3/(A center dot min).

Combining information from multispectral image fusion can enhance human and machine perception. Currently, multiple luminescent materials with different spectral responses are used, which requires complex algorithms and systems to solve the problem of pixel and position mismatch. To overcome above deficiencies, a series of Bi3 + /Ln3+-codoped Cs2Ag0.6Na0.4InCl6 (Ln3+ = Tm3+, Er3+, Nd3+, Yb3+) double perovskites were synthesized. Under 365 nm excitation, Bi3+/Tm3+-codoped Cs2Ag0.6Na0.4InCl6 shines efficient warm-white emission band at 610 nm and the multiple near-infrared (NIR) emission bands at 810, 1220, and 1430 nm, which stems from selftrapped exciton emission and f-f transition of Tm3+, respectively. Beside that, Bi3+/Tm3+-codoped Cs2Ag0.6Na0.4InCl6 also emits bright radioluminescence with a light yield of 34000 +/- 1000 photons/MeV under X-ray irradiation. Particularly, a large-area and ultra-flexible 0.5 %Bi3+/12 %Tm3+-codoped Cs2Ag0.6Na0.4InCl6/polydimethylsiloxane (PDMS) film was prepared, and its applications in white light, NIR, and X-ray imaging were demonstrated, respectively. Moreover, a pixel-level X-ray to NIR image fusion was realized without pixel mismatch and complex imaging processing, and the structural information of centrifuge tube and screw inside the capsule is obtained in a fusion image. Finally, the 3D image of the capsule and its internal structure was successfully reconstructed by combining multiangle imaging and multispectral image fusion.

Regarding global energy scarcity issues, it is imperative to establish sustainable plant production systems to promote smart agriculture. Addressing the critical demands of plant lighting and X-ray imaging in smart agriculture, a recyclable luminescent flexible film is developed on a filter paper and organic Cu(I) metal iodide, and establishes a bifunctional platform integrating plant growth lighting and plant root X-ray imaging. Specifically, [Ca(15-crown-5)2]Cu4I6·2C3H7NO·H2O and [Ca2(18-crown-6)4]Cu4I8·6H2O are synthesized through supramolecular assembly, which show yellow emission with the near-unity luminous efficiency under 450 nm excitation. Moreover, organic Cu(I) iodides exhibit bright X-ray radioluminescence with a maximum light yield of 110200 photons per MeV. Subsequently, a paper-based customizable large-area flexible film is prepared in situ through "ancient cloth dyeing process", and demonstrates its application in single-component white light emitting diode and X-ray imaging. Combined white light and X-ray image fusion as well as multiangle imaging, the flexible film in the application of 3D image reconstruction is demonstrated. Furthermore, the flexible film can be recycled and reused in a N, N-dimethylformamide solution while maintaining excellent stability. Considering that the flexible film can be degraded by microorganisms in natural soil into plant nutrients and participate in the carbon loop, it is conducive to achieving carbon neutrality.

Electrohydrodynamic (EHD) jet printing represents a novel micro/nano-scale additive manufacturing process that utilises a high-voltage induced electric field between the nozzle and the substrate to print micro/nanoscale structures. EHD printing is particularly advantageous for the fabrication on flexible or non-flat substrates and of large aspect ratio micro/nanostructures and composite multi-material structures. Despite this, EHD printing has yet to be fully industrialised due to its low throughput, which is primarily caused by the limitations of serial additive printing technology. The parallel multi-nozzle array-based process has become the most promising option for EHD printing to achieve large-scale printing by increasing the number of nozzles to realise multichannel parallel printing. This paper reviews the recent development of multi-nozzle EHD printing technology, analyses jet motion with multi-nozzle, explains the origins of the electric field crosstalk effect under multi-nozzle and discusses several widely used methods for overcoming it. This work also summarises the impact of different process parameters on multi-nozzle EHD printing and describes the current manufacturing process using multi-nozzle as well as the method by which they can be realised independently. In addition, it presents an additional significant utilisation of multi-nozzle printing aside from enhancing single-nozzle production efficiency, which is the production of composite phase change materials through multi-nozzle. Finally, the future direction of multi-nozzle EHD printing development is discussed and envisioned.

Interdigital electrodes (IDEs) have been widely utilized in environmental monitoring, biomedicine, food safety, etc. However, existing technologies still face challenges in fabricating highly sensitive IDEs with high resolution and large height. This work presents a new method for preparing IDEs using non-contact electric-field-driven (NEFD) 3D printing. The copper foil is mounted on an insulated nozzle as an extraction electrode to generate an electric field with the substrate through electrostatic induction. The consistent printing of line width and line spacing of IDEs and the law of large height printing are investigated. IDEs with line width, line spacing of 10 mu m, and height of 20 mu m were obtained by optimizing the printing process. The sensitivity of the IDEs could reach up to 53120 Omega/ppm with a detection limit of 0.01 ppm using sulfate solutions with different concentrations (0.01-100 ppm). This method provides a new approach for preparing high resolution, large height IDEs.

Drug development and precision therapy are core technologies in the biopharmaceutical field.In the traditional paradigm,new drug development relies on validation through animal testing and clinical trials—a process that requires a decade of testing and costs over two billion dollars[1].Although animal testing has long served as the standard approach for evaluating drug effi-cacy and toxicity,its predictive accuracy for human responses re-mains limited due to translational barriers arising from interspecies physiological differences[2].

Correction for ‘Recent progress in eutectic gallium indium (EGaIn): surface modification and applications’ by Wensong Ge et al., J. Mater. Chem. A, 2024, 12, 657–689, https://doi.org/10.1039/D3TA04798A.

EGaIn plays an important role in flexible electronics, this paper focuses on a review of the key factors affecting the surface tension of liquid metals and surface modification methods and applications.

Polydimethylsiloxane (PDMS) with excellent stretchability and biocompatibility, has been widely used as a flexible substrate for wearable and stretchable electronics. However, the drawback of poor tear resistance of PDMS greatly limits its applications, such as flexible electronics. Herein, a gradient structure Ecoflex-PDMS-Ecoflex (E-P-E) combining PDMS and Ecoflex was proposed by combining multi-material 3D printing with functional gradient material design to improve the tear resistance of flexible substrates. The E-P-E gradient structure substrate has a 73 times increase in fracture energy and a 7 times increase in tear strength compared with conventional PDMS substrates. Liquid metal-based strain sensors made with our designed E-P-E gradient structure substrate can be directly worn on the finger with low hysteresis (0.47%), good cyclic stability (0.04% change in sensitivity after 1000 cycles of 100% strain), and high strain range (>180%), which showed a broad application prospect in the fields of human motion monitoring and human-computer interaction.

The applications of 3D curved electronics, such as conformal antennas, smart aircraft skins, and structural health monitoring, encompass a wide range of applications. However, the integrated fabrication of 3D curved multi layer electronics with high resolution and high performance remains a major challenge, especially on free-form surfaces. Here, a novel conformal 3D printing technique based on locally polarized electric-field-driven (LP-EFD) vertical jet printing has been proposed for the fabrication of high-resolution, high-performance 3D curved electronic devices. The simulation results demonstrate that it has a highly stable and symmetric distributed electric field to produce a steady and vertically downward jet, ensuring high-precision and high-resolution 3D curved/conformal printing. The printing parameters were optimized by exploring their effect on line width and printing consistency. Several typical 3D curved circuits such as single-layer circuit patterns on different curved surface, multilayer circuit patterns on cylindrical structure surfaces, and curved transparent heaters have been printed successfully. The resulting circuits achieve the smallest line width of 8 mu m, the largest height difference 50 mm, and high line width consistency (less than +/- 3.7 %). The fabricated 3D curved circuit exhibits excellent conductivity of 4.44x107 S/m and high adhesion (resistance changes less than 1 % after 100 times peeling). The proposed fabrication method provides a novel solution for exploring high-resolution 3D curved conformal circuits and curved multilayer electronic devices.

Conductive polymers (CPs) have been widely used as electrode materials in supercapacitors because of their facile synthesis, low cost, and high capacitance. However, their practical application in micro-supercapacitors (MSCs) has been hindered by the manufacturing complexity and dimensional limits due to their low process -ability, and the very poor cycle-life due to its volumetric change in the charge-discharge process. Here, we present CPs-based MSCs with a unique structure of polypyrrole (PPy)@Ag-wall interdigitated electrodes fabri-cated by combing micro-3D printing Ag-wall and electrochemical polymerization of PPy. Benefiting from the unique structure and effective interface of PPy@Ag-wall interdigitated electrodes, these all-solid-state MSCs (S < 0.25 cm2) offer an area capacitance (C/A) up to 90 mF cm-2, coupled with a long cycle-life (capacitance remains 109 % after 10,000 cycles), great flexibility (capacitance remains 95 % after bending for 1000 times), and a very low interfacial resistance (2.88 omega). In conclusion, this unique design of the PPy@Ag-wall interdigitated electrode structure not only achieves the formation of the arbitrary structure of CPs, but also greatly improves its cycle-life, promoting the CPs-based MSCs for the future miniature energy storage device.

This paper presents a new method for fabricating transparent antennas using metal mesh. A transparent microstrip antenna for application at 2.45 GHz is fabricated on a glass using electric-field-driven (EFD) microscale 3D printing combined with a micro-plating process, obtaining a sheet resistance of less than 0.4 Ω/sq and 78% transparency, which also achieves good impedance matching and good agreement between simulation and measurement. Compared to traditional methods such as photolithography and laser writing, it reduces manufacturing costs and enhances the conductivity of low-temperature-cured silver paste materials. Additionally, it also enables customization, providing a cost-effective and efficient solution for the production of transparent metal mesh antennas.

Highly active bifunctional electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have always been the key factors to affect the performance of zinc-air batteries. However, integrating the independent reaction sites of ORR and OER in a catalyst remains a major challenge. Herein, a collaborative strategy based on defect induction and doping is proposed to prepare the strain-regulated Pt-NiO@Ni sub-micron particles (Pt-NiO@Ni SP). Benefiting from the synergistic effect of tensile strain and Pt-doped, the metallic Ni-based sub-micron particles with tensile strain as the catalyst carriers can effectively optimize the electronic distribution of atomic structures in Pt and NiO on the surface of particles, leading to reduce the energy barrier of intermediates for ORR and OER. Consequently, the Pt-NiO@Ni SP exhibits outstanding bifunctional catalytic activity with the ΔE index of 0.65 V under a low Pt loading, outperforming that of the benchmark Pt/C+IrO2 catalysts (0.76 V). Impressively, the Pt-NiO@Ni SP-based liquid zinc-air battery develops a high open-circuit potential (1.47 V), excellent energy density (188.2 mW cm-2 ), and favorable cyclic charge-discharge cycling durability (200 h at 20 mA cm-2 ). This work provides an innovative avenue for the rational construction of highly active bifunctional electrocatalysts for practical applications.

Electrohydrodynamic (EHD) jet printing, as one of the most popular micro/nano-scale additive manufacturing methods, is still facing challenges in large-height printing and conformal printing due to poor electric field stability. The newly proposed electric field-driven (EFD) jet 3D printing has claimed better electric field stability. To reveal changing behaviour and generation mechanism of the electric field in 3D printing, an electric field model for EFD jet 3D printing was built and further validated by simulation and experiments (line width and critical voltage vs. printing height). Then, the advantage of the EFD method over EHD was confirmed by a case application of conformal printing with a height difference of larger than 9 mm and a multi-layer structure with a height of 5 mm and a line width of 20 μm. Therefore, the EFD jet 3D printing offers the possibility of achieving 3D printing in a larger height range with better electric field stability.

Thin-walled tubular mesh structures are the basic form of tubular scaffolds, such as vascular and nerve conduit stents, in tissue engineering. A novel electric field-driven microscale three-dimensional printing (EFD μ-3D printing) was proposed for manufacturing these structures of molten polymers with high resolution. For printing on curved substrates, the distributions of electric field force on substrates with different curvature radii in the self-excited electrostatic field were revealed via numerical simulations. The optimal process parameters for EFD μ-3D printing on curved substrates were determined. To improve printing accuracy, a micro-area preset eccentricity strategy was proposed by reducing the vertical angle of printing jets. A number of printing cases have been carried out. It is shown that the proposed method is effective for the micro-nano scale printing of 3D structures. The printed structures have good flexibility; they can be restored to their original state after 8.9 % axial compression, with an original length of 67 mm. Moreover, a conformal printing variable stiffness thin-wall tubular mesh structure has been achieved with a length of 28 mm, a line diameter of 80 μm, a big end diameter of 8 mm, and a small end diameter of 4 mm.

Ordered graphene/polymer composites have gained significant research interest due to their electrical con-ductivity, mechanical strength, and thermal stability. However, great challenges remain in achieving high-efficiency vat photopolymerization 3D printing of high-performance ordered graphene/polymer composites due to the low printing speed and the decreased ductility caused by the polymerization difficulty from the light-absorbing and shadowing of graphene nanoplatelets. Here, an electrically assisted continuous vat photo-polymerization 3D printing technology using a dual-cure polymer (photo/thermal) is proposed for fabricating the high-performance ordered graphene/polymer composites. Firstly, process parameters (graphene content, printing speed, and light intensity) in the 3D printing were optimized and investigated on the composites with various graphene contents. Then, the relationship of the graphene nanoplatelets arrangement and the intensity of the electric field was established. Subsequently, multiple mechanical properties of ordered composites resulted from various graphene amounts were systematically investigated. Our results demonstrated that compared to the pure polymer, the ordered 2 wt% graphene/polymer composite has a 101% higher tensile strength (89 oa), 200% higher total elongation (27.69%), 126% higher flexural strength (139.9 oa and 20.6%), and 98% higher fracture strain. Besides, the electrical conductivity of the polymer composite with ordered graphene structure was 15 times higher than that of the random polymer composite. Thus, the proposed electrically assisted continuous vat photopolymerization 3D printing with photo/thermal dual-curing polymer matrix not only successfully realizes the continuous fabrication of ordered graphene/polymer composites, but also improves mechanical properties (both strength and ductility) and electrical conductivity.