Composite Ink Research Articles

Photoluminescent Y2O3:Eu3+@PVA composite dispersions and films for anti-counterfeiting ink applications

The development of high-tech anti-counterfeiting inks to detect counterfeit products is a crucial task for almost every aspect of modern life around the world. Herein, we report the synthesis of photoluminescent xY2O3:Eu3+@PVA (x = 0, 1, 2.5, 5, 10, 15, and 20 wt%) composite dispersions and films and demonstrate their potential for anti-counterfeiting inks applications. Laser-synthesized m-Y2O3:Eu3+ nanoparticles (daver = 20.3 ± 6.9 nm) with strong red luminescence due to 5D0 → 7F0-4 transitions of Eu3+ were used as a pigment to create luminescent composites. Detailed photoluminescence properties of the obtained composite dispersions and films as a function of m-Y2O3:Eu3+ content were investigated in combination with SEM, EDX, UV–Vis and IR spectroscopy data. Tuning of the CIE coordinates of xY2O3:Eu3+@PVA is observed by changing the excitation wavelength. The results of SEM showed that the photoluminescent nanoparticles were uniformly distributed in the PVA film. Photoluminescent m-Y2O3:Eu3+-doped PVA composite inks can be applied via spray, brush, and screen-printing techniques to create security features on various surfaces, including glass, ceramics, paper, plastics, and currency notes. These inks remain stable for at least four months and offer a distinctive luminescent signature that is challenging to replicate, owing to the unique photoluminescence spectrum of Eu3+ in the monoclinic Y2O3 polymorph.

A Stone‐Cottage‐Inspired Printing Strategy to Build Microsphere Patterned Scaffolds for Accelerated Bone Regeneration

AbstractThe physical microtopography, in an effective and stable manner, can powerfully confer biomaterials with enhanced osteoconduction for the repair of critical‐sized bone defects. However, the realization of the osteoconductive microtopography within a 3D porous scaffold is still unmet. Herein, this work presents a stone‐cottage‐inspired printing strategy to build microsphere patterned scaffolds with a tunable microtopography for accelerated bone regeneration. The customized composite inks of poly (lactic‐co‐glycolic acid) microspheres as “Stone” and alginate hydrogels as “Mortar” endow the fibers of as‐printed scaffolds with a stable and tunable groove‐ridge microstructure. Owing to this microtopography, microsphere patterned scaffolds significantly promote cell recruitment, immune response, angiogenesis, and osteogenesis. Meanwhile, compared to 55 and 85 µm, 25 µm width of groove‐ridge microstructure displays the most osteoconduction for repair of critical bone defects. Mechanistically, while cells prefer to adhere to microstructure with a bigger width and higher modulus in the early phase, this microstructure should also act as a barrier for cell growth and its smaller width is more beneficial for cell communication and differentiation in the later phase. Overall, it provides a robust strategy to fabricate the osteoconductive microtopography within a 3D scaffold, broadening the manipulation of physical morphology in tissue engineering.

Engineering the Atomic Interface of Refractory‐Metal‐Reinforced Copper Matrix Using Direct Ink 3D Printing

Herein, 3D printing involving metallic materials with substantially distinct melting temperatures and their immiscibility presents a formidable challenge. Nevertheless, it may be possible to overcome this challenge using the direct ink writing (DIW) method within such immiscible systems. In this article, a successful fabrication of Cu‐based composites utilizing the additive manufacturing process that is DIW technique, followed by a post‐sintering process, is presented. The secondary addition to the Cu–matrix includes tantalum (Ta), tungsten (W), and niobium (Nb). The rheological properties of the composite inks are also analyzed for the DIW technique. The underlying reasons behind the increased mechanical, wear, and thermal properties are assessed through experimental and molecular dynamics simulations. Microstructural analysis is conducted using optical and scanning electron microscopes. Mechanical, electrical, thermal, and wear properties are evaluated at ambient temperature, and comparisons are established with DIW‐processed pure Cu. Elemental mapping through energy‐dispersive spectroscopy and high‐resolution transmission electron microscopy confirm the distribution of W, Ta, and Nb particles within the composite. The 3D printing of immiscible alloy components opens new avenues for exploring novel material properties, mixtures, and composite materials, thus fostering the development of innovative materials.

Generalisation of the yield stress measurement in three point bending collapse tests: application to 3D printed flax fibre reinforced hydrogels

This paper describes the extrusion pressure's effect on composite hydrogel inks' filaments subjected to three point bending collapse tests. The composite considered in this work consists of an alginate-poloxamer hydrogel reinforced with flax fibres. Increased extrusion pressure resulted in more asymmetrical filaments between the support pillars. Furthermore, the material and printing conditions used in the present study led to the production of curved specimens. These two characteristics implicitly limit the validity of the yield stress equations commonly used in open literature. Therefore, a new system of equations was derived for the case of asymmetrical and curved filaments. A post-processing method was also created to obtain the properties required to evaluate this yield stress. This new equation was then implemented to identify the strength of failed hydrogels without flax fibre reinforcement. A statistical analysis showed this new equation's significance, which yielded statistically higher (i.e. 1.15 times larger) strength values compared to the numbers obtained with the open literature equations. At larger extrusion pressures, longer periods were needed for the material to converge towards its final shape. Larger extrusion pressure values led to lower yield stresses within the composite hydrogel filament: a 5 kPa increase in extrusion pressure lowered the yield stress by 19%. In comparison, a 15 kPa increase led to a 29% decrease in the yield stress. Overall this study provides guidelines to standardize three point bending collapse tests and analysis comparison between different materials.

Liquid metal-enhanced composite conductive ink with improved electrical stability and durability for flexible electronics

For flexible electronics, conductive ink is a critical material with diverse applications. However, conventional inks, like those based on nano-silver, are expensive and result in printed patterns with limited conductivity stability. To address these limitations and enhance overall electrical performance, stability, and durability, this study developed a novel composite conductive ink incorporating liquid metal and silver microparticles. We fabricated conductive patterns and extensively investigated the sintering process, focusing on how liquid metal content and sintering techniques affect the resulting patterns' electrical performance and stability. Our findings reveal that incorporating liquid metal introduces a slight trade-off in the initial conductivity. However, subsequent thermal and hot-press sintering treatments significantly improve conductivity, with hot-press sintering leading to the most pronounced enhancement. Furthermore, the addition of liquid metal substantially bolsters the electrical stability of the patterns. Notably, conductive patterns fabricated using a 1:1 mass ratio of the ink exhibit ∆R/R0 values of only 1.72 and 0.432 after 5000 bending cycles, following thermal and hot-press sintering, respectively. This highlights the significant improvement in electrical stability and durability achieved by incorporating liquid metal into the conductive ink.

3D printing of aligned silk fibroin microfibers covered with nitrogen-doped carbon dots for anti-counterfeiting

Counterfeiting has serious economic and social consequences, prompting researchers worldwide to develop innovative and highly secure anti-counterfeiting methods, including the use of various polymer printing techniques and the integration of functional materials to create patterns with customized designs that are easy to detect and cannot be falsified. Composite inks made of silk fibroin microfibers and polyvinyl alcohol or polyethylene glycol were developed to produce patterns with the microstructures aligned in the direction of extrusion during the 3D printing process. Fibroin microfibers were obtained via high temperature treatment and used as a precursor for carbon dot synthesis. This approach allowed the microfiber structure to be maintained and be amenable to the synthesis of carbon dots doped with N-heteroatom on its surface, resulting in a material that fluoresces bright blue when irradiated at 365 nm but remains invisible in normal lighting conditions

MATHEMATICAL MODEL OF NICKEL-GRAPHENE COMPOSITE INKS FOR JETTING PROPERTIES IN INKJET PRINTING

The droplet formation process in inkjet printing is studied numerically and verified through a simulation model. The droplet formation process decides the printing quality of the coating, and a mathematical model is developed to understand the complete process from droplet formation to detachment. The Navier-Stokes equation is used to mathematically derive the droplet radius (rnumerical). COMSOL multiphysics is used for simulation and the radius (rsimulation) is calculated from the droplet mass. The rnumerical and rsimulation are compared for inks containing nickel, graphene, and nickel-graphene composite ink it is observed that the composite ink radiuses have the lowest difference (rsimulation - rnumerical =0.085µm). A droplet is formed at 1.47mm from the nozzle inlet, for nickel-graphene ink, and after 1.5mm for other pristine inks. The results are verified through Z number, velocity profile, and droplet mass. The droplet formation observed from the velocity profile is earliest at 120µs. It is seen that a stable droplet is generated at 100µs for nickel-graphene ink and at 200 µs for individual inks.

Study on Printability Evaluation of Alginate/Silk Fibroin/Collagen Double-Cross-Linked Inks and the Properties of 3D Printed Constructs.

In recent years, biological 3D printing has garnered increasing attention for tissue and organ repair. The challenge with 3D-printing inks is to combine mechanical properties as well as biocompatibility. Proteins serve as vital structural components in living systems, and utilizing protein-based inks can ensure that the materials maintain the necessary biological activity. In this study, we incorporated two natural biomaterials, silk fibroin (SF) and collagen (COL), into a low-concentration sodium alginate (SA) solution to create novel composite inks. SF and COL were modified with glycidyl methacrylate (GMA) to impart photo-cross-linking properties. The UV light test and 1H NMR results demonstrated successful curing of silk fibroin (SF) and collagen (COL) after modification and grafting. Subsequently, the printability of modified silk fibroin (RSFMA)/SA with varying concentration gradients was assessed using a set of three consecutive printing models, and the material's properties were tested. The research results prove that the addition of RSFMA and ColMA enhances the printability of low-concentration SA solutions, with the Pr values increasing from 0.85 ± 0.02 to 0.90 ± 0.03 and 0.92 ± 0.02, respectively, and the mechanical strength increasing from 0.19 ± 0.01 to 0.28 ± 0.01 and 0.38 ± 0.01 MPa; cytocompatibility has also been improved. Furthermore, rheological tests indicated that all of the inks exhibited shear thinning properties. CCK-8 experiments demonstrated that the addition of ColMA increased the cytocompatibility of the ink system. Overall, the utilization of SF and COL-modified SA materials as inks represents a promising advancement in 3D-printed ink technology.

High-temperature thin-film strain sensors with low temperature coefficient of resistance and high sensitivity via direct ink writing

High-temperature thin-film strain sensors are advanced technological devices for monitoring stress and strain in extreme environments, but the coupling of temperature and strain at high temperature is a challenge for their use. Here, this issue is addressed by creating a composite ink that combines Pb2Ru2O6 and TiB2 using polysilazane (PSZ) as a binder. After direct writing and annealing the PSZ/Pb2Ru2O6/TiB2 film at 800 °C in air, the resulting thin film exhibits a low temperature coefficient of resistance (TCR) of only 281 ppm/°C over a wide temperature range from 100 °C to 700 °C, while also demonstrating high sensitivity with a gauge factor approaching 19.8. This exceptional performance is attributed to the intrinsic properties of Pb2Ru2O6, which has positive TCR at high temperature, and TiB2, which has negative TCR at high temperature. Combining these materials reduces the overall TCR of the film. Tests showed that the PSZ/Pb2Ru2O6/TiB2 film maintains stable strain responses and significant signal output even under varying temperature. These findings provide valuable insights for developing high-temperature strain sensors with low TCR and high sensitivity, highlighting their potential for applications in high-temperature strain measurements.

Precision 3D printing of chitosan-bioactive glass inks: Rheological optimization for enhanced shape fidelity in tissue engineering scaffolds

3D printing technology in tissue engineering applications provides several advantages for scaffold development, especially with natural materials, such as chitosan, which provides a biomimetic environment for cellular growth. However, chitosan hydrogel-based inks still show poor printing fidelity. In this article, we overcame this challenge by incorporating bioactive glasses (BG) nanoparticles (up to 5 wt%) into the chitosan hydrogel. The resulting inks were characterized by rheological tests, while their processability was evaluated through measurements of shape fidelity. An indirect cytotoxicity assay was also conducted to evaluate the cell viability of the printed scaffolds. The results indicated that adding BG nanoparticles to the chitosan-based ink modified its rheological properties and improved its shape-fidelity during 3D printing, which we suggest are consequences of hydrogen bonds established between the glass and the chitosan chains. Also, cytotoxicity assessment demonstrated that the resulting scaffold exhibits high cell viability. In conclusion, the proposed composite ink has optimized rheological properties for 3D printing and is promising for applications in tissue engineering.

Directly Printable, Non‐Smearable and Stretchable Conductive Ink Enabled by Liquid Metal Microparticles Interstitially Engineered in Highly Entangled Elastomeric Matrix

AbstractLiquid metal or liquid metal microparticles (LMP) based conductive inks, though promising for fabrication of circuits for use in soft and stretchable electronics, are constrained by a few drawbacks such as need for encapsulation, need for sintering to induce conductivity, and smearing. To address these issues, herein, a stretchable conductive composite ink is developed by combining LMPs with carbon black (CB) in highly entangled polysiloxane elastomer. LMP‐dispersed elastomer lacks conductivity because of its non‐percolated network, however, the CB can interconnect LMPs to act as a bridge, thereby imparting conductivity to the elastomer. Due to presence of fluidic LMPs, the LMPs‐dispersed elastomer lies in soft regime with initial conductivity of 5.6 S m−1, aided by the presence of CB in the interstitial spaces between the LMPs. The highly entangled molecular network of the encapsulating elastomer endows the resulting composite with high stretchability (≈286%) and softness (0.648 MPa) and its long pot life enables rheological modulation of the ink to achieve pressure‐driven direct printed non‐smearing traces. The LMPs‐based conductive ink developed in this work is expected to be further utilized in the fabrication of soft robotics and electronic skin and integrated into electronic modules by facile direct 3D printing.

Polycaprolactone strengthening gelatin/nano-hydroxyapatite composite biomaterial inks for potential application in extrusion-based 3D printing bone scaffolds

Extrusion-based three-dimensional (3D) printing of gelatin (Gel) is crucial for fabricating bone tissue engineering scaffolds via additive manufacturing. However, the thermal instability of Gel remains a persistent challenge, as it tends to collapse at mild temperatures. Current approaches often involve simply mixing Gel particles with various materials, resulting in biomaterial inks that lack uniformity and have inconsistent degradation characteristics. In this study, acetic acid was used to dissolve Gel and polycaprolactone (PCL) separately, producing homogeneous Gel/PCL dispersions with optimal pre-treatment performance. These dispersions were then combined and hybridized with nano-hydroxyapatite (n-HA) to create a composite printing ink. By evaluating the printability of the ink, the optimal conditions were identified: a n-HA concentration of 50% (w/w), a printing temperature of 10–15 ℃, a printing pressure of 2.5 bar, and a printing speed of 7 mm/s. The resulting biomaterial inks, with a composition of 25% Gel, 25% PCL, and 50% n-HA, demonstrated excellent printability and stability, along with significantly enhanced mechanical properties. As a result, 3D scaffolds with high printability and shape fidelity can be printed at room temperature, followed by deep freezing at -80 ℃ and cross-linking with vanillin. The Gel-based composite scaffolds demonstrated excellent biocompatibility, cell adhesion, cell viability and nano-hydroxyapatite absorption in vitro. Additionally, in vivo experiments revealed that the bioactive scaffold biodegraded during implantation and significantly promoted bone regeneration at the defect site. This provides a promising strategy for treating bone defects in clinical setting. In conclusion, the Gel/PCL/n-HA biomaterial inks presented here offer an innovative solution for extrusion bioprinting in the field of bone tissue engineering.Graphical

High performance pixelated quantum dots array on Micro-LED by inkjet printing

Micro-LED display has risen to prominence in research and industry, distinguished by their numerous advantages. Quantum dots (QDs) film, serving as color conversion layers (CCLs) for Micro-LED, are considered a leading candidate for the next generation of displays, owing to their low power consumption and broad color gamut. Inkjet printing stands out as a feasible approach for crafting QDs CCLs. The essence of the process hinges on attaining a printed QDs film that boasts both uniformity and high-precision QDs array. However, the unstable printing of QDs ink significantly impacts the surface morphology of QDs arrays and the display performance of Micro-LEDs. Therefore, elucidating the mechanism behind the unstable printing of QDs in inkjet printing and fabricating QDs is of paramount importance. In this study, through the simulation of unstable printing with conventional QDs ink, we identified nozzle blockage and the rapid evaporation of low-boiling-point ink as the primary causes of unstable printing. This leads to aggregation and deposition of QDs, obstructing the nozzle and altering the fluid path. A novel binary organic composite ink was employed to print the QDs array on the substrate with ultra-stability, achieving a high yield and greatly reduced coffee-ring effect Micro-LED full-color display.

3D printing cross‐scale mold for manufacturing micromixers

AbstractNowadays, the methods of manufacturing microfluidic mixers were not flexible enough to customize and manufacture special sizes. Hence, a novel electrohydrodynamic jet printing method was proposed to fabricate cross‐scale mold for manufacturing micromixers in one step. Polyvinylpyrrolidone (PVP)/polycaprolactone (PCL) composite ink was prepared, and various printing parameters were investigated for fabricating varieties of 2D structures and 3D regular molds. A cross‐scale spiral mixer was successfully printed, various diameter ratio of 5.6, aspect ratio of 7.2. The PVP/PCL lines were direct printed, size of 66 nm deep and 743 nm wide. The circles were size of 564 nm deep and 7.02 μm wide. The mixing conditions of micromixers with different width ratios were simulated and analyzed; and the better mixing effect of micromixers with width ratio of 2:1 was proved, improved the mixing efficiency by 15.6% compared with micromixer without cross‐scale channels. The cross‐scale micromixers are promising for skin chip sensor and drug metabolite analysis, and the printing method proposed in this paper has great application potential in micro‐electro‐mechanical systems (MEMS).

Multifunctional and high-performance electrothermal films based on carbon black/Ag nanowires/graphene composites

Fabricating high-conductive composites and constructing highly conductive networks are crucial for high-performance electrothermal film. In this study, an Ag nanowires/graphene (Ag/G) composite synthesized by liquid-phase exfoliation and in-situ photoreduction is mixed with carbon black (CB) to form a composite conductive ink, and a CB/Ag/G composite electrothermal film with a point-line-plane three-dimensional microstructure is obtained via blade coating process. Both the addition of Ag nanowires and a subsequent compression rolling treatment induce the establishment of the effective conductive network in the film, endowing it with an outstanding conductivity of 399.4 S cm−1. The film reaches a Ts of 204 °C with an input voltage of 3.0 V, and is successfully applied in water heating and de-icing, demonstrating its extraordinary electrothermal performance and vast potential for practical applications. The film is also used as an electromagnetic shielding film and heat dissipation substrate, showing exceptional electromagnetic shielding (42.5 dB) and heat dissipation properties.

A wearable, rapidly manufacturable, stability-enhancing microneedle patch for closed-loop diabetes management

The development of a wearable, easy-to-fabricate, and stable intelligent minisystem is highly desired for the closed-loop management of diabetes. Conventional systems always suffer from large size, high cost, low stability, or complex fabrication. Here, we show for the first time a wearable, rapidly manufacturable, stability-enhancing microneedle patch for diabetes management. The patch consists of a graphene composite ink-printed sensor on hollow microneedles, a polyethylene glycol (PEG)-functionalized electroosmotic micropump integrated with the microneedles, and a printed circuit board for precise and intelligent control of the sensor and pump to detect interstitial glucose and deliver insulin through the hollow channels. Via synthesizing and printing the graphene composite ink, the sensor fabrication process is fast and the sensing electrodes are stable. The PEG functionalization enables the micropump a significantly higher stability in delivering insulin, extending its lifetime from days to weeks. The patch successfully demonstrated excellent blood glucose control in diabetic rats. This work may introduce a new paradigm for building new closed-loop systems and shows great promise for widespread use in patients with diabetes.

Printable MXene Ink Hybridized with ZSM-5 for Gas Sensing and CO2 Capturing

In this work we present preparation, characterization and microprinting of Ti3C2/ZSM-5 ink. Printable inks with a viscosity of 5-6 cP were prepared by ultrasonic dispersion of Ti3C2/ZSM-5 nanopowders in DMSO solvent using 1% Polyvinylpyrrolidone (PVP) as dispersant. Brunauer Emmett Teller (BET) results indicate a type IV adsorption isothermal curve for N2 gas with a type H4 retention ring. The data show that the average pore size of the composite material is 23nm, indicating that the material has a micro-mesoporous structure and exhibits excellent adsorption properties for gas sensing applications. However, the adsorption and desorption curves of CO2 shows hysteresis indicating strong interaction between functional groups on the material and CO2 molecules. This material has high CO2 adsorption performance and desorption hysteresis effect, indicating that it can be directly used for CO2 capture. Thermogravimetric (TGA) analysis showed the thermal stability of the composite, with a mass loss of only 5% at 800℃. Ti3C2/ZSM-5 composite ink has excellent anti-oxidation and dispersion properties. When the pure MXene interlayer void is exposed to air, the Ti element in MXene is easily oxidized to TiO2. The introduction of ZSM-5 not only limits the interaction between the functional groups on the surface of MXene, but also fills the layer gap of MXene, effectively reduces the contact with oxygen, and thus shows good oxidation resistance. No characteristic valence signal of TiO2 was observed in XPS results, which confirmed the effectiveness of the method. In addition, imidazole acid molecular sieve frame strengthened MXene adsorption, will have broad prospect of application in gas sensing field. In traditional printing methods, such as drop casting and spin coating, it is difficult to control the uniformity and roughness of coating thickness, which affects the service life and sensing properties of gas sensors. The use of spray atomization technology can maximize the uniform dispersion of ink, and can control the amount of spray, concentration, height and other parameters to control the thickness and roughness of the coating.

Direct Ink Writing of SiCN/RuO2/TiB2 Composite Ceramic Ink for High-Temperature Thin-Film Sensors.

Direct ink writing (DIW) of high-temperature thin-film sensors holds significant potential for monitoring extreme environments. However, existing high-temperature inks face a trade-off between cost and performance. This study proposes a SiCN/RuO2/TiB2 composite ceramic ink. The added TiB2, after annealing in a high-temperature atmospheric environment, forms B2O3 glass, which synergizes with the SiO2 glass phase formed from the SiCN precursor to effectively encapsulate RuO2 particles. This enhances the film's density and adhesion to the substrate, preventing RuO2 volatilization at high temperatures. Additionally, the high conductivity of TiB2 improves the film's overall conductivity. Test results indicate that the SiCN/RuO2/TiB2 film exhibits high linearity from room temperature to 900 °C, high stability (resistance drift rate of 0.1%/h at 800 °C), and high conductivity (4410 S/m). As a proof of concept, temperature sensors and a heat flux sensor were successfully fabricated on a metallic hemispherical surface. Performance tests in extreme environments using high-power lasers and flame guns verified that the conformal thin-film sensor can accurately measure spherical temperature and heat flux, with a heat flux sensor response time of 53 ms. In conclusion, the SiCN/RuO2/TiB2 composite ceramic ink developed in this study offers a high-performance and cost-effective solution for high-temperature conformal thin-film sensors in extreme environments.

3D-printed β-TCP/Ti6Al4V composite scaffolds for bone regeneration: Process parameter optimization and evaluation

A β-TCP/Ti6Al4V composite scaffold with interconnected macro porous architecture was fabricated using Direct Ink Writing (DIW). Pluronic F-127 and de-ionized water was used as binder and solvent for ink preparation. The present work was carried out to study the rheological behavior of the composite bioceramic ink and to investigate DIW process parameters such as Ti6Al4V proportion, infill percentage and extrusion pressure. The Box-Behnken response surface methodology, ANOVA, sensitivity, desirability approach are used for the experimental, statistical and numerical optimization of the parameters suitable for DIW. The output responses such as dimensional error of the fabricated scaffold from the original dimensions and compressive strength are considered for multi-objective optimization. The result defined that the optimal values are solid loading 55 %v/v (40 %v/v of β-TCP, 15 %v/v of Ti6Al4V) and 45 %v/v of Pluronic gel, 98 % infill rate and 6.36 bar pressure. The dimensional error and compressive strength of the scaffold printed at the optimized conditions are found as 1.88 % and 19 MPa with macro and micro pores suitable for bone regeneration with satisfactory biocompatibility assed via MTT assay.

Integrating High-Performance Flexible Wires with Strain Sensors for Wearable Human Motion Detection.

Flexible electronics have revolutionized the field by overcoming the rigid limitations of traditional devices, offering superior flexibility and adaptability. Conductive ink performance is crucial, directly impacting the stability of flexible electronics. While metal filler-based inks exhibit excellent conductivity, they often lack mechanical stability. To address this challenge, we present a novel conductive ink utilizing a ternary composite filler system: liquid metal and two micron-sized silver morphologies (particles and flakes). We systematically investigated the influence of filler type, mass ratio, and sintering process parameters on the composite ink's conductivity and mechanical stability. Our results demonstrate that flexible wires fabricated with the liquid metal/micron silver particle/micron silver flake composite filler exhibit remarkable conductivity and exceptional bending stability. Interestingly, increasing the liquid metal content results in a trade-off, compromising conductivity while enhancing mechanical performance. After enduring 5000 bending cycles, the resistance change in wires formulated with a 4:1 mass ratio of micron silver particles to flakes is only half that of wires with a 1:1 ratio. This study further investigates the mechanism governing resistance variations during flexible wire bending. Additionally, we observed a positive correlation between sintering temperature and pressure with the conductivity of flexible wires. The significance of the sintering parameters on conductivity follows a descending order: sintering temperature, sintering pressure, and sintering time. Finally, we demonstrate the practical application of this technology by integrating the composite ink-based flexible wires with conductive polymer-based strain sensors. This combination successfully achieved the detection of human movements, including finger and wrist bending.