High-resolution Printing Research Articles

Engineering multifunctional UV-polymerizable imidazolidinyl urea-based methacrylate resin for 3D printing: Synthesis, characterization, and antimicrobial properties

3D photo printing provides immense flexibility in shaping polymeric objects with intricate geometries. However, the limited availability of photoactive resins for 3D printing poses numerous challenges in realizing the desired material properties in terms of accuracy, printing resolution, and the tunability of mechanical and biodegradable characteristics. To encounter this, researchers consistently strive to develop new photoresins with multifunctional capabilities. Herein, we have reported for the first time, an easy and straightforward synthesis of imidazolidinyl urea (IU) based photoactive resins for high-resolution 3D printing. Our study delves into the impact of photoinitiator, viscosity, photoinhibitor, and photoabsorber on the 3D printing process. Moreover, a comprehensive examination of the physicochemical properties, encompassing thermal, mechanical, and biodegradation behavior reveals the tunability of these properties by adjusting the monomer-to-crosslinker ratio. Furthermore, our printed polymers exhibited strong antimicrobial properties against gram-positive bacteria B. subtilis and gram-negative bacteria E. coli while maintaining minimal toxicity towards mouse fibroblast (NIH-3 T3) cells. In summary, our newly developed IU-based resin emerges as a competitive alternative, addressing the growing demand for advanced photoresins with superior high-resolution 3D printing capabilities, particularly in biomedical applications. This important achievement not only expands the possibilities of 3D printing technology but also presents a versatile solution with promising implications for various biomedical needs.

High-Resolution Printing of Various Electronic Materials by Electrophotography

Electrophotography is a digital, on-demand, dry, and page printing technique that operates based on toner particles of electronic materials using an electrostatic force and generates an electrical circuit via distribution of the toner particles. We developed a 10 μm linewidth resolution with various electronic materials, including conductors, semiconductors, and insulators, without any chemical pretreatments on the substrate films, while a 5 μm resolution was also possible for limited materials. The electrical resistivity of the printed Ag–Ni after an intense pulse light sintering was comparable to that of commercial indium tin oxide transparent films.

3D printed grafts with gradient structures for organized vascular regeneration

Synthetic vascular grafts suitable for small-diameter arteries (<6 mm) are in great need. However, there are still no commercially available small-diameter vascular grafts (SDVGs) in clinical practice due to thrombosis and stenosis after in vivo implantation. When designing SDVGs, many studies emphasized reendothelization but ignored the importance of reconstruction of the smooth muscle layer (SML). To facilitate rapid SML regeneration, a high-resolution 3D printing method was used to create a novel bilayer SDVG with structures and mechanical properties mimicking natural arteries. Bioinspired by the collagen alignment of SML, the inner layer of the grafts had larger pore sizes and high porosity to accelerate the infiltration of cells and their circumferential alignment, which could facilitate SML reconstruction for compliance restoration and spontaneous endothelialization. The outer layer was designed to induce fibroblast recruitment by low porosity and minor pore size and provide SDVG with sufficient mechanical strength. One month after implantation, the arteries regenerated by 3D-printed grafts exhibited better pulsatility than electrospun grafts, with a compliance (8.9%) approaching that of natural arteries (11.36%) and significantly higher than that of electrospun ones (1.9%). The 3D-printed vascular demonstrated a three-layer structure more closely resembling natural arteries while electrospun grafts showed incomplete endothelium and immature SML. Our study shows the importance of SML reconstruction during vascular graft regeneration and provides an effective strategy to reconstruct blood vessels through 3D-printed structures rapidly.

Roll-to-roll, high-resolution 3D printing of shape-specific particles

Particle fabrication has attracted recent attention owing to its diverse applications in bioengineering1,2, drug and vaccine delivery3–5, microfluidics6,7, granular systems8,9, self-assembly5,10,11, microelectronics12,13 and abrasives14. Herein we introduce a scalable, high-resolution, 3D printing technique for the fabrication of shape-specific particles based on roll-to-roll continuous liquid interface production (r2rCLIP). We demonstrate r2rCLIP using single-digit, micron-resolution optics in combination with a continuous roll of film (in lieu of a static platform), enabling the rapidly permutable fabrication and harvesting of shape-specific particles from a variety of materials and with complex geometries, including geometries not possible to achieve with advanced mould-based techniques. We demonstrate r2rCLIP production of mouldable and non-mouldable shapes with voxel sizes as small as 2.0 × 2.0 µm2 in the print plane and 1.1 ± 0.3 µm unsupported thickness, at speeds of up to 1,000,000 particles per day. Such microscopic particles with permutable, intricate designs enable direct integration within biomedical, analytical and advanced materials applications.

Direct printing of conductive hydrogels using two-photon polymerization

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) based conductive hydrogels have been extensively used for bioelectronics and tissue engineering applications owing to their high electrical conductivity and ability to interface with soft biological tissues. However, the fabrication of PEDOT:PSS-based hydrogels has mostly relied on conventional fabrication techniques such as casting and transfer printing, which limits the feature size to micro- or mesoscale. To address these limitations, this study offers a novel PEDOT:PSS-based hydrogel material that can be printed directly to nano/microscale structures using the Two-Photon Polymerization (TPP) technique. The TPP-printability of the newly developed hydrogel was analyzed, and its printing window was characterized. The prepared hydrogel exhibits enhanced radial swelling, electrical properties, and biocompatibility compared to the pristine PEDOT:PSS. To validate the micro-manufacturing feasibility of hydrogel, several microstructures were fabricated using the TPP process. The fabricated microstructures demonstrate many properties, including electrical conductivity, biocompatibility, high resolution, and structural stability. The direct printing of highly conductive PEDOT:PSS hydrogel micro-devices overcomes the limitations of traditional conductive hydrogel manufacturing methods. It opens up new possibilities for applications in micro-energy storage devices, flexible micro/nanoelectromechanical systems (MEMS), and flexible biomedical micro-devices. The combination of high-resolution direct printing and unique hydrogel properties offers promising opportunities in these fields.

In-vivo integration of soft neural probes through high-resolution printing of liquid electronics on the cranium

Current soft neural probes are still operated by bulky, rigid electronics mounted to a body, which deteriorate the integrity of the device to biological systems and restrict the free behavior of a subject. We report a soft, conformable neural interface system that can monitor the single-unit activities of neurons with long-term stability. The system implements soft neural probes in the brain, and their subsidiary electronics which are directly printed on the cranial surface. The high-resolution printing of liquid metals forms soft neural probes with a cellular-scale diameter and adaptable lengths. Also, the printing of liquid metal-based circuits and interconnections along the curvature of the cranium enables the conformal integration of electronics to the body, and the cranial circuit delivers neural signals to a smartphone wirelessly. In the in-vivo studies using mice, the system demonstrates long-term recording (33 weeks) of neural activities in arbitrary brain regions. In T-maze behavioral tests, the system shows the behavior-induced activation of neurons in multiple brain regions.

High-Throughput Two-Photon 3D Printing Enabled by Holographic Multi-Foci High-Speed Scanning.

The emerging two-photon polymerization (TPP) technique enables high-resolution printing of complex 3D structures, revolutionizing micro/nano additive manufacturing. Various fast scanning and parallel processing strategies have been proposed to promote its efficiency. However, obtaining large numbers of uniform focal spots for parallel high-speed scanning remains challenging, which hampers the realization of higher throughput. We report a TPP printing platform that combines galvanometric mirrors and liquid crystal on silicon spatial light modulator (LCoS-SLM). By setting the target light field at LCoS-SLM's diffraction center, sufficient energy is acquired to support simultaneous polymerization of over 400 foci. With fast scanning, the maximum printing speed achieves 1.49 × 108 voxels s-1, surpassing the existing scanning-based TPP methods while maintaining high printing resolution and flexibility. To demonstrate the processing capability, functional 3D microstructure arrays are rapidly fabricated and applied in micro-optics and micro-object manipulation. Our method may expand the prospects of TPP in large-scale micro/nanomanufacturing.

Improving the Three-Dimensional Printability of Potato Starch Loaded onto Food Ink.

This study focuses on improving the 3D printability of pea protein with the help of food inks designed for jet-type 3D printers. Initially, the food ink base was formulated using nanocellulose-alginate with a gradient of native potato starch and its 3D printability was evaluated. The 3D-printed structures using only candidates for the food ink base formulated with or without potato starch exhibited dimensional accuracy exceeding 95% on both the X and Y axes. However, the accuracy of stacking on the Z-axis was significantly affected by the ink composition. Food ink with 1% potato starch closely matched the CAD design, with an accuracy of approximately 99% on the Z-axis. Potato starch enhanced the stacking of 3D-printed structures by improving the electrostatic repulsion, viscoelasticity, and thixotropic behavior of the food ink base. The 3D printability of pea protein was evaluated using the selected food ink base, showing a 46% improvement in dimensional accuracy on the Z-axis compared to the control group printed with a food ink base lacking potato starch. These findings suggest that starch can serve as an additive support for high-resolution 3D jet-type printing of food ink material.

Visible-Light-Driven Rapid 3D Printing of Photoresponsive Resins for Optically Clear Multifunctional 3D Objects.

Light-driven 3D printing is gaining significant attention for its unparalleled build speed and high-resolution in additive manufacturing. However, extending vat photopolymerization to multifunctional, photoresponsive materials poses challenges, such as light attenuation and interference between the photocatalysts (PCs) and photoactive moieties. This study introduces novel visible-light-driven acrylic resins that enable rapid, high-resolution photoactive 3D printing. The synergistic combination of a cyanine-based PC, borate, and iodonium coinitiators (HNu 254) achieves an excellent printing rate and feature resolution under low-intensity, red light exposure. The incorporation of novel hexaarylbiimidazole (HABI) crosslinkers allows for spatially-resolved photoactivation upon exposure to violet/blue light. Furthermore, a photobleaching mechanism inhibited by HNu 254 during the photopolymerization process results in the production of optically-clear 3D printed objects. Real-time Fourier transform infrared spectroscopy validates the rapid photopolymerization of the HABI-containing acrylic resin, whereas mechanistic evaluations reveal the underlying dynamics that are responsible for the rapid photopolymerization rate, wavelength-orthogonal photoactivation, and observed photobleaching phenomenon. Ultimately, this visible-light-based printing method demonstrates: (i) rapid printing rate of 22.5mm h-1, (ii) excellent feature resolution (≈20µm), and (iii) production of optically clear object with self-healing capability and spatially controlled cleavage. This study serves as a roadmap for developing next-generation "smart" 3D printing technologies.

Application of machine learning in 3D bioprinting of cultivated meat

Cultivated meat production, an innovative and sustainable alternative to conventional animal farming, has gained significant attention in recent years. As the demand for ethical and environmentally friendly protein sources continues to rise, the need for efficient and scalable production strategies becomes critical. Notably, the integration of advanced technology, such as machine learning (ML), can enhance the efficiency of the cultivated meat production process. The goal of this review paper is to highlight the advantages and limitations of various ML approaches and provide a balanced discussion on the integration of ML techniques for three-dimensional (3D)-bioprinted cultivated meat. This review paper explores the application of ML techniques in various facets of 3D-bioprinted cultivated meat and highlights the potential for ML to optimize various aspects of the process, from predicting printability and optimizing printing parameters to characterizing meat flavor and monitoring meat quality. ML plays a pivotal role in optimizing the material formulation to improve ink printability and identifying an optimal combination of printing parameters to achieve high printing resolution and accuracy. Furthermore, ML can aid in modeling sensory attributes, ensuring that the cultivated meat replicates the desired meat flavor. Finally, ML can be applied for meat quality control as it facilitates the automated detection of harmful pathogens, ensuring the safety and consistency of 3D-bioprinted cultivated meat.

Ionically annealed zwitterionic microgels for bioprinting of cartilaginous constructs

Foreign body response (FBR) is a pervasive problem for biomaterials used in tissue engineering. Zwitterionic hydrogels have emerged as an effective solution to this problem, due to their ultra-low fouling properties, which enable them to effectively inhibit FBR in vivo. However, no versatile zwitterionic bioink that allows for high resolution extrusion bioprinting of tissue implants has thus far been reported. In this work, we introduce a simple, novel method for producing zwitterionic microgel bioink, using alginate methacrylate (AlgMA) as crosslinker and mechanical fragmentation as a microgel fabrication method. Photocrosslinked hydrogels made of zwitterionic carboxybetaine acrylamide (CBAA) and sulfobetaine methacrylate (SBMA) are mechanically fragmented through meshes with aperture diameters of 50 and 90 µm to produce microgel bioink. The bioinks made with both microgel sizes showed excellent rheological properties and were used for high-resolution printing of objects with overhanging features without requiring a support structure or support bath. The AlgMA crosslinker has a dual role, allowing for both primary photocrosslinking of the bulk hydrogel as well as secondary ionic crosslinking of produced microgels, to quickly stabilize the printed construct in a calcium bath and to produce a microporous scaffold. Scaffolds showed ∼20% porosity, and they supported viability and chondrogenesis of encapsulated human primary chondrocytes. Finally, a meniscus model was bioprinted, to demonstrate the bioink’s versatility at printing large, cell-laden constructs which are stable for further in vitro culture to promote cartilaginous tissue production. This easy and scalable strategy of producing zwitterionic microgel bioink for high resolution extrusion bioprinting allows for direct cell encapsulation in a microporous scaffold and has potential for in vivo biocompatibility due to the zwitterionic nature of the bioink.

Fast and Facile Liquid Metal Printing via Projection Lithography for Highly Stretchable Electronic Circuits.

Soft electronic circuits are crucial for wearable electronics, biomedical technologies, and soft robotics, requiring soft conductive materials with high conductivity, high strain limit, and stable electrical performance under deformation. Liquid metals (LMs) have become attractive candidates with high conductivity and fluidic compliance, while effective manufacturing methods are demanded. Digital light processing (DLP)-based projection lithography is a high-resolution and high-throughput printing technique for primarily polymers and some metals. If LMs can be printed with DLP as well, the entire soft devices can be fabricated by one printer in a streamlined and highly efficient process. Herein, fast and facile DLP-based LM printing is achieved. Simply with 5-10 s of patterned ultraviolet (UV)-light exposure, a highly conductive and stretchable pattern can be printed using a photo-crosslinkable LM particle ink. The printed eutectic gallium indium traces feature high resolution (≈20 µm), conductivity (3 × 106 S m-1), stretchability (≈2500%), and excellent stability (consistent performance at different deformation). Various patterns are printed in diverse material systems for broad applications including stretchable displays, epidermal strain sensors, heaters, humidity sensors, conformal electrodes for electrography, and multi-layer actuators. The facile and scalable process, excellent performance, and diverse applications ensure its broad impact on soft electronic manufacturing.

Three-dimensional blueprinting of molecular patterns in liquid crystalline polymers.

Exploiting the interplay of anisotropic diamagnetic susceptibility of liquid crystalline monomers and site selective photopolymerization enables the fabrication of 3D freeforms with highly refined microstructures. Utilizing chain transfer agents in the mesogenic inks presents a pathway for broadly tuning the mechanical properties of liquid crystalline polymers and their response to stimuli. In particular, the combination of 1,4-benzenedimethanethiol and tetrabromomethane is shown to enable voxelated blueprinting of molecular order, while allowing for a modulation of the crosslink density and the mechanical properties. The formulation of these monomers allows for the resolution of the voxels to approach the limits set by the coherence lengths defined by the anchoring from surfaces. These compositions demonstrate the expected thermotropic responses while allowing for their functionalization with photochromic switches to elicit photomechanical responses. Actuation strains are shown to outstrip that accomplished with prior systems that did not access chain transfer agents to modulate the structure of the macromolecular network. Test cases of this system are shown to create freeform actuators that exploit the refined director patterns during high-resolution printing. These include topological defects, hierarchically-structured light responsive grippers, and biomimetic flyers whose flight dynamics can be actively modulated via irradiation with light.

Recent innovations in interfacial strategies for DLP 3D printing process optimization.

Three-dimensional (3D) printing, also known as additive manufacturing, is capable of transforming computer-aided designs into intricate structures directly and on demand. This technology has garnered significant attention in recent years. Among the various approaches, digital light processing (DLP) 3D printing, which utilizes polymers or prepolymers as the ink, has emerged as the leading new technology, driven by high demand across diverse fields such as customized production, healthcare, education, and art design. DLP 3D printing technology employs cured slices as molding units and is recognized for its potential to achieve both high printing speed and resolution. Recent insights into the DLP printing process highlight its inherent interface transformations between liquid and solid states. This review summarizes key aspects of the printing process, speed, precision, and material diversity optimization, from the view of interfacial interactions between solid and liquid phases which are influenced by resin formation, curing surfaces and light source properties. These interactions include those at the liquid resin-UV pattern interface, the cured structure-curing surface interface, the liquid resin-curing surface interface, and the liquid resin-cured structure interface, each contributing to the unique characteristics of the printed results. Finally, this review addresses the current challenges and limitations of DLP 3D printing, providing valuable insights for future improvements and guiding potential innovations in the field.

High-resolution low-cost LCD 3D printing for microfluidics and organ-on-a-chip devices.

The fabrication of microfluidic devices has progressed from cleanroom manufacturing to replica molding in polymers, and more recently to direct manufacturing by subtractive (e.g., laser machining) and additive (e.g., 3D printing) techniques, notably digital light processing (DLP) photopolymerization. However, many methods require technical expertise and DLP 3D printers remain expensive at a cost ∼15-30 K USD with ∼8 M pixels that are 25-40 μm in size. Here, we introduce (i) the use of low-cost (∼150-600 USD) liquid crystal display (LCD) photopolymerization 3D printing with ∼8-58 M pixels that are 18-35 μm in size for direct microfluidic device fabrication, and (ii) a poly(ethylene glycol) diacrylate-based ink developed for LCD 3D printing (PLInk). We optimized PLInk for high resolution, fast 3D printing and biocompatibility while considering the illumination inhomogeneity and low power density of LCD 3D printers. We made lateral features as small as 75 μm, 22 μm-thick embedded membranes, and circular channels with a 110 μm radius. We 3D printed microfluidic devices previously manufactured by other methods, including an embedded 3D micromixer, a membrane microvalve, and an autonomous capillaric circuit (CC) deployed for interferon-γ detection with excellent performance (limit of detection: 12 pg mL-1, CV: 6.8%). We made PLInk-based organ-on-a-chip devices in 384-well plate format and produced 3420 individual devices within an 8 h print run. We used the devices to co-culture two spheroids separated by a vascular barrier over 5 days and observed endothelial sprouting, cellular reorganization, and migration. LCD 3D printing together with tailored inks pave the way for democratizing access to high-resolution manufacturing of ready-to-use microfluidic and organ-on-a-chip devices by anyone, anywhere.

Tissue-specific gelatin bioink as a rheology modifier for high printability and adjustable tissue properties.

Decellularized extracellular matrix (dECM) has emerged as an exceptional biomaterial that effectively recapitulates the native tissue microenvironment for enhanced regenerative potential. Although various dECM bioinks derived from different tissues have shown promising results, challenges persist in achieving high-resolution printing of flexible tissue constructs because of the inherent limitations of dECM's weak mechanical properties and poor printability. Attempts to enhance mechanical rigidity through chemical modifications, photoinitiators, and nanomaterial reinforcement have often compromised the bioactivity of dECM and mismatched the desired mechanical properties of target tissues. In response, this study proposes a novel method involving a tissue-specific rheological modifier, gelatinized dECM. This modifier autonomously enhances bioink modulus pre-printing, ensuring immediate and precise shape formation upon extrusion. The hybrid bioink with GeldECM undergoes a triple crosslinking system-physical entanglement for pre-printing, visible light photocrosslinking during printing for increased efficiency, and thermal crosslinking post-printing during tissue culture. A meticulous gelatinization process preserves the dECM protein components, and optimal hybrid ratios modify the mechanical properties, tailoring them to specific tissues. The application of this sequential multiple crosslinking designs successfully yielded soft yet resilient tissue constructs capable of withstanding vigorous agitation with high shape fidelity. This innovative method, founded on mechanical modulation by GeldECM, holds promise for the fabrication of flexible tissues with high resilience.

A photocurable polyurethane elastomer for digital light processing with comprehensive reusability based on dynamic hindered urea bonds

Digital Light Processing (DLP) 3D printing has emerged as a highly promising technique, enabling the fabrication of intricate geometric structures with ease and precision, without the need for complex mold-making processes. However, the printed objects are typically crosslinked photopolymers that cannot be reshaped, reprocessed and recycled. Herein, we successfully synthesize a dynamic soft polymer crosslinker containing hindered urea bonds (HUBs) composed of polyurethane acrylate prepolymer and tri-functional for recyclable DLP 3D printing. Contributing to the dynamic thermal response of HUBs, the printed objects can be recycled in the initial printing inks at 80 °C in 2h and the obtained recycled ink can be reprinted by DLP achieving a low viscosity and high printing resolution. In addition, the printed objects can be reprocessed by hot-press at 110 °C for 30 min upon a pressure of 5 MPa. By a reasonable proportion of monomer and crosslinker, a series of photocured elastomers were successfully prepared, in which mechanical properties could be tailored by changing the content of the crosslinker. The resulting products exhibited some fascinating attributes, such as excellent fatigue resistance, thermodynamic stability, and transparency. Significantly, the resin can regain initial 3D printing capability after undergoing solvent recycling, which maintains its printing resolution and excellent mechanical properties. This innovative design strategy not only alleviates environmental impact but also plays a pivotal role in developing the DLP 3D printing industry by tackling the long-standing issue of resin recyclability.

3-oxetanylmethanol as additive to PEDOT:PSS for improved conductivity and water-resistance and applications in ink-jet printed electrochemical transistors

3-oxetanylmethanol is used as additive to poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) water dispersions and the properties of thin films, prepared by spin-coating and ink-jet printing, either on glass or flexible polyethylene terephthalate (PET) substrates, are investigated. 1H NMR studies revealed that 3-oxetanylmethanol is reactive within the PEDOT:PSS medium during the film drying step at 120 °C, to form polyether compounds. Chemical cross-linking established through the esterification reaction of pendant hydroxyl groups in polyether chains, resulting from the 3-oxetanylmethanol in situ polymerization, and sulfonate groups from PSS, is also identified by the 1H NMR studies. Spin-cast films prepared from this formulation on either glass or PET exhibited electrical conductivity enhanced by more than two orders of magnitude, when compared to films obtained with the pristine PEDOT:PSS dispersion, reaching maximum values of around 596 and 682 Scm−1 for films on glass and PET, respectively, together with improved water-resistance. Atomic force microscopy and Raman spectroscopic studies, indicating that PEDOT chains are organized in more ordered domains in the films of the oxetane-based formulations, suggest that the polyether compounds modify the PEDOT:PSS phase segregation and promote charge transport across conducting PEDOT segments. Subsequently, improved conductivities and stability were also found for films prepared by high-resolution ink-jet printing of the formulations that led to the most conductive spin coated films. The potential application of the new ink formulations in printed electrodes interfacing aqueous media was assessed by ink-jet printing PEDOT-based electrochemical transistors operating with aqueous KCl electrolyte.

3D printing dielectric elastomers for advanced functional structures: A mini‐review

AbstractThree‐dimensional (3D) printed bionic products play an important role in intelligent robotics, microelectronics, and polymers. The printing and manufacturing process of 3D printers is conducive to obtaining soft structures that meet specific requirements, and saves time and cost. Soft intelligent robotics, an emerging research field, has always been developed based on soft materials and actuators with their biological properties. This article reviews the current understanding of 3D bioprinting technologies for dielectric elastomers (DEs), DE actuators (DEAs) and soft robots, such as inkjet, extrusion, laser‐induced and stereolithography bioprinting. 3D printers for fabricating soft materials are presented and classified. The approaches to exploit 3D bioprinters for DEs/DEAs are as follows: (1) 3D printing DEAs utilize ionic hydrogel–elastomer hybrids that are analogous to human muscles, and the DEAs usually have flexible structures and large deformations with multiple functionalities. (2) An electrohydrodynamic (EHD) 3D printer confers high printing resolution and high production efficiency, which offers advantages such as full automation and flexible design. The optimal printing conditions are mainly determined by the effects of printing voltages and ink properties, which are related to the formation of the liquid cone and the printed line width. Furthermore, the advantages of 3D bioprinting technologies have accelerated their development and applications.

Printed High-Adhesion Flexible Electrodes Based on an Interlocking Structure for Self-Powered Intelligent Movement Monitoring.

Two-dimensional transition metal carbide nitrides (MXenes) have been extensively explored in diverse areas, such as electrochemical energy storage and flexible electronics. Although the solution-processed MXene-based device has made significant achievements, it is still a challenge to develop large-scale and high-resolution printing methods for flexible printed electronics. In this work, we reported a novel strategy of a porous interlocking structure to obtain flexible MXene/laser-induced graphene (LMX) composite electrodes with enhanced adhesion and high printing resolution. In comparison to traditional printed MXene electrodes, the LMX electrode with an interlocking interface possesses enhanced mechanical properties (adhesive strength of 2.17 MPa) and comparable electrical properties (0.68 S/mm). Furthermore, owing to the outstanding stability and flexibility, the LMX-based triboelectric nanogenerator (TENG) can be used as a self-powered sensor to monitor finger-bending movement. A support vector machine (SVM)-assisted self-powered motion sensor can distinguish the bending angle with high recognition accuracy and can effectively identify different angles. The successful experience of directly printing flexible electrodes with excellent mechanical and electrical properties can be promoted to other solution-processed two-dimensional materials. Our strategy opens up a promising perspective to develop flexible and printed electronics.