Additive manufacturing最新文献

{"title":"Fast and accurate auto-disturbances-rejection temperature control system based on particle swarm optimized fuzzy control: Applied for particle three-dimensional (3D) printing prosthetic orthotic plate","authors":"Biaoqiang Liu ,&nbsp;Bo Qian ,&nbsp;Yuxin Liang ,&nbsp;Peng Dai ,&nbsp;Ruidi Li ,&nbsp;Qingsong Wei","doi":"10.1016/j.addma.2025.104704","DOIUrl":"10.1016/j.addma.2025.104704","url":null,"abstract":"<div><div>In traditional temperature control system of particle 3D printing extrusion device, it exists many issues such as slow response speed, large fluctuation, and poor anti-interference ability. The above issues cause the instability of the extruded PLA filament, affecting the mechanical properties and surface quality of the printed samples. Based on particle swarm optimization algorithm, this paper proposes a precise control method for temperature control system to iteratively optimize the quantization factor and proportion factor, finally it obtains the optimal weight factor. Compared with traditional PID control and fuzzy PID control, response speed has improved by 58.6 % and 40.0 % respectively, overshoot has reduced by 76 % and 35 % respectively, and steady-state time has shortened to 24 s. Comparison of experimental results: The tensile strength of the samples increases by 15.52 % and 7.47 % respectively, the bending strength increases by 17.93 % and 11.58 % respectively, and the internal pores are improved significantly. In summary, the method proposed in this paper can effectively solve the problems of the temperature control system for particle 3D printing, and improve the mechanical properties and surface quality of the samples. The printed prosthetic orthotic plate can well meet the fitness and comfort of the human body.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104704"},"PeriodicalIF":10.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freeze-dried silver nanowire based resin formulation for vat photopolymerization 3D printing of stretchable and electrically conductive nanocomposites","authors":"Khai Yang Tan ,&nbsp;Wen Siong Poh ,&nbsp;Nor Azam Endot ,&nbsp;Poi Sim Khiew ,&nbsp;Chuan Yi Foo ,&nbsp;Hong Ngee Lim","doi":"10.1016/j.addma.2025.104706","DOIUrl":"10.1016/j.addma.2025.104706","url":null,"abstract":"<div><div>Vat photopolymerization (VPP) 3D printing is well suited for high-throughput production of intricate parts, making it ideal for soft electronics fabrication. This necessitates the development of VPP-printed stretchable-conductive nanocomposites (VPP-SCN), which currently exhibit limited conductivities (&lt;0.1 mS cm⁻¹) due to restricted conductive-filler concentration (CFC) to ensure resin’s printability and nanocomposite’s stretchability. Incorporating high aspect ratio (AR) conductive fillers can achieve superior conductivity at low CFC, but is hindered by ultrasonication-induced filler fractures in conventional dispersion methods. Herein, freeze drying is introduced to process high-AR silver nanowires, resulting in freeze-dried silver nanowires (f-AgNWs) that dispersible in resin via low-speed magnetic stirring, avoiding conventional ultrasonication. Due to their high AR, coplanar alignment of the f-AgNWs is induced during the layer-by-layer VPP process. This results in printed f-AgNW nanocomposites that exhibit anisotropic conductivity, with layer-perpendicular and layer-parallel conductivities of 5 mS cm⁻¹ and 110 mS cm⁻¹ respectively, demonstrating a significant enhancement over the existing VPP-SCN. The high AR of f-AgNWs facilitates the stated conductivity at low CFC of 5 wt%, preserving printability. Low CFC and AgNWs alignment also enable good stretchability (127 %), mechanical durability (32 %, 1000 cycles), and electrical stability (gauge factor = 1.38) of the nanocomposite. The achieved properties enable fully-printed functional applications, as demonstrated by a touch-detecting capacitive sensor, and a stretchable interconnect that maintains LED illumination under strain. This work provides valuable insights into achieving high conductivity without significantly compromising printability and stretchability, thereby enabling the potential utilization of VPP in the development and fabrication of soft electronics.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104706"},"PeriodicalIF":10.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate detection of local porosity in laser powder bed fusion through deep learning of physics-based in-situ infrared camera signatures","authors":"Berkay Bostan,&nbsp;Shawn Hinnebusch,&nbsp;David Anderson,&nbsp;Albert C. To","doi":"10.1016/j.addma.2025.104701","DOIUrl":"10.1016/j.addma.2025.104701","url":null,"abstract":"<div><div>Porosity critically impacts the reliability and performance of metal laser powder bed fusion (LPBF) parts, affecting properties like fracture toughness and fatigue life. This work proposes a deep learning (DL) framework to predict local porosity in LPBF Inconel 718 parts using in-situ infrared (IR) camera imaging where parts are produced under standard conditions, resulting in 0.03 % overall porosity. The framework achieves over 90 % balanced accuracy for detecting pores above 34 μm at a 360 μm sensor resolution. First, input features include six physics-based IR signatures (cooling rate, heat intensity, interpass temperature, relative melt pool area, spatter generation, and maximum predeposition temperature) and local scan vector length, all linked to porosity generation mechanisms. Second, the framework considers feature interactions across the current pixel and its 26 nearest neighbors. Third, special convolutional filters are developed to filter heat intensity and cooling rate features at edges and stripe boundaries, compensating for limited camera resolution in those regions. Ground truth data on pore size and locations are gathered through serial sectioning and optical microscopy. In unseen parts with varying geometrical features, the framework achieves a true positive rate above 88 % and a false negative rate below 4 % for pores over 34 μm. The proposed DL framework is rigorously compared to traditional machine learning models, demonstrating its superiority in terms of faster training, higher prediction speed, smaller size, and robust performance on unseen test blocks. Additionally, Shapley Additive Explanations analysis elucidates pore formation mechanisms, revealing complex feature interactions across different regimes. Results align well with known pore formation mechanisms, indicating that the developed algorithm interprets complex relationships between features and porosity. This work enhances in-situ porosity detection in LPBF and advances the understanding of pore formation mechanisms.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104701"},"PeriodicalIF":10.3,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating elastic and thermal contributions to lattice strains from operando X-ray diffraction measurements using fast simulations","authors":"S. Gaudez ,&nbsp;D. Weisz-Patrault ,&nbsp;K.A. Abdesselam ,&nbsp;H. Gharbi ,&nbsp;V. Honkimäki ,&nbsp;S. Van Petegem ,&nbsp;M.V. Upadhyay","doi":"10.1016/j.addma.2025.104674","DOIUrl":"10.1016/j.addma.2025.104674","url":null,"abstract":"<div><div>Lattice strains obtained from <em>operando</em> synchrotron X-ray diffraction measurements during metal additive manufacturing are being increasingly used to estimate temperature evolution during the process. At the minimum, these transient lattice strains have contributions from thermal and elastic strains. Temperature estimates from lattice strains have thus far been extracted assuming that elastic strains are negligible in comparison to thermal strains at high temperatures when the heat source is close to the probed region. However, such an assumption may not only lead to inaccuracies in estimating temperature but also fail to correctly estimate the non-negligible stress evolution occurring at moderate to low temperatures as the heat source moves away. Numerical simulations can be used to predict lattice strains but these predictions are necessarily different from experimental measures.</div><div>This work proposes an experimentally corrected numerical approach to improve simulation predictions. It involves first using a recently developed fast numerical thermomechanics model to predict lattice strains. Then, the predicted thermal and elastic strains are corrected using a minimization procedure under the strict constraint that the predicted lattice strains are strictly equal to the measured ones, thus improving the original estimates. This strategy is demonstrated for <em>operando</em> synchrotron X-ray diffraction measurements during directed energy deposition of a thin wall made from 316L stainless steel, which exhibits negligible solid-state phase transformations. Following validation, the corrected thermal and elastic strains are used to estimate temperature and stress evolution and study the difference in temperature and heating/cooling rate prediction caused by neglecting elastic strains.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104674"},"PeriodicalIF":10.3,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying thermal effects during 3D printing by comparing in-layer infrared pre- and postheating of carbon fiber reinforced polyamide 6","authors":"Ole S. Nesheim ,&nbsp;Sindre W. Eikevåg ,&nbsp;Martin Steinert ,&nbsp;Christer W. Elverum","doi":"10.1016/j.addma.2025.104705","DOIUrl":"10.1016/j.addma.2025.104705","url":null,"abstract":"<div><div>Additive manufacturing technologies, particularly Material Extrusion (MEX), are rapidly evolving and gaining widespread adoption. However, parts produced by MEX often suffer from poor out-of-plane mechanical properties. Thus, to learn more about the fusion process of succeeding layers, this study investigates and compares the thermal and strength effects of in-layer infrared (IR) pre- and postheating during MEX 3D printing of carbon fiber reinforced polyamide 6 (PA6-CF). An experimental setup using a ∼40 W halogen bulb as an auxiliary heater was developed to compare no heating, preheating, and postheating configurations at print speeds ranging from 3 to 50 mm/s to manufacture single-wall tensile samples with 0.8 mm wall thickness and 0.3 mm layer height. Layer temperature, T_L, and maximum temperature resulting from the external heater, T_H, were measured for all heating configurations using infrared imaging. Thermal increase, ΔT_Pre, and ΔT_Post was calculated from these two values and compared at various print speeds. An experimental estimate of thermal increase, ΔT_T, was also defined to aid in the explanation of the observed strength effects and how they relate to the thermal evolution of the layer fusion process. Tensile testing was conducted to evaluate interlayer strength and correlated to the thermal measurements.</div><div>Results revealed thermal increase caused by IR heating at slower speeds and residual heat accumulation at higher speeds, both positively impacting strength. Postheating showcased a maximum T_H of 272.9 ± 5.2°C and a maximum UTS of 59.84 MPa whereas preheating exhibited 219.2 ± 2.8°C and 52.28 MPa at a print speed of 3 mm/s. In addition, postheating demonstrated tensile samples with fracture across several layers, indicating strong layer adhesion. Even though postheating was found to be more effective at lower speeds, preheating produced stronger tensile tests at higher speeds. In answer to this result, the study introduces the concept of Layer Fusion Evolution (LFE) to hypothesize on how the two top layers fuse together under the different IR heating configurations. Based on the insights from the presented hypothesis and the experimental estimate of thermal increase, a model is presented and compared to the strength results as a possible explanation of why preheating and postheating performs differently across various print speeds. This model exhibits the same trend as the strength measurements across different speeds, and due to the previously linked property of weld temperature and strength, supports the presented hypothesis.</div><div>Furthermore the paper discusses future work and implementation of the findings and how they may aid in optimizing auxiliary heating strategies for MEX processes to improve out-of-plane mechanical properties and reduce the anisotropy in 3D printed components.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104705"},"PeriodicalIF":10.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complex shaped Al2O3/YAG/ZrO2 eutectic ceramics with excellent high temperature mechanical properties printed by vat photopolymerization","authors":"Shuqi Hao ,&nbsp;Haijun Su ,&nbsp;Di Zhao ,&nbsp;Xiang Li ,&nbsp;Zhonglin Shen ,&nbsp;Yuan Liu ,&nbsp;Yinuo Guo ,&nbsp;Zhuo Zhang ,&nbsp;Min Guo","doi":"10.1016/j.addma.2025.104703","DOIUrl":"10.1016/j.addma.2025.104703","url":null,"abstract":"<div><div>Directionally solidified oxide eutectic ceramics exhibit excellent performances at both room and high temperatures due to strong phase interface binding, which determines broad application prospects in the field of ultra-high temperature structural components. However, oxide eutectic ceramics prepared by current directional solidification techniques are unable to simultaneously possess large volumes, complex shapes, and uniformly fine eutectic structures. In this study, complex shaped Al₂O₃/YAG/ZrO₂ eutectic ceramic hollow guide blades with nearly full relative density and uniformly fine eutectic microstructure were successfully prepared for the first time, utilizing a combination of laser floating zone melting, vat photopolymerization 3D printing and hot isostatic pressing. Sintered eutectic ceramics with fully closed porosity achieving a relative density of 91.97 ± 1.25 % were obtained by pressureless sintering at 1670℃ for 2 h. Al₂O₃/YAG/ZrO₂ sintered eutectic ceramics with a relative density of 99.27 ± 0.22 % were obtained by hot isostatic pressing at 1550℃ with 200 MPa for 60 min. The sintered highly densed eutectic ceramic exhibited a bending strength of 352.99 ± 39.97 MPa at room temperature. This bending strength can remain a value of 299.38 MPa at 1500°C, which is corresponding to a high strength retention rate of 84.81 %. Additionally, the hardness was 19.10 ± 0.69 GPa and the fracture toughness was 2.22 ± 0.21 MPa·m^1/2. This work offers a novel solution for the preparation of complex shaped oxide eutectic ceramic components.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104703"},"PeriodicalIF":10.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation-enabled healable and stretchable shape-memory polymer composites for digital light processing 4D printing","authors":"Wei Huang ,&nbsp;Wenqing Chen ,&nbsp;Vikramjeet Singh ,&nbsp;Jianhui Zhang ,&nbsp;Yu Wang ,&nbsp;Mohammed Alabdullatif ,&nbsp;Eral Bele ,&nbsp;Gary J. Lye ,&nbsp;Helen C. Hailes ,&nbsp;Manish K. Tiwari","doi":"10.1016/j.addma.2025.104699","DOIUrl":"10.1016/j.addma.2025.104699","url":null,"abstract":"<div><div>4D printing provides viable pathways for 3D-printed objects that require morphological, time-dependent adaptations. Among various 4D printing materials, shape-memory polymers (SMPs) are one of the most extensively utilized morphing materials. However, most existing SMPs in 4D printing systems suffer from irreparability and low stretchability due to abundant covalently cross-linked networks. Also, their shape-programming steps typically involve stringent temperature requirements (≥90 ºC) and lack strategies for remote controllability, significantly restricting their applicability. Herein, we report a novel thermoplastic polymer system with self-healing and highly stretchable shape-memory capabilities for digital light processing (DLP)-based 4D printing. This system was attained through the integration of two distinct compositions: a polymer-based framework that acts as the reinforcing phase; and an elastic lubricant featuring hydrogen bonds that facilitates self-healing, high stretchability, and enhanced shape recovery. Additionally, light-responsive capabilities were shown to be effectively achieved by introducing a novel cross-linker functionalized with biomass lignin. The rationally selected safer set of ingredients ensures that our printed shape-memory polymer composites (SMPCs) are biocompatible. We further demonstrate their potential applications in aerospace and healthcare. This work provides a foundation for the design and facilitation of intelligent materials, showcasing excellent properties across multiple fields.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104699"},"PeriodicalIF":10.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiphysics optimization of additive manufacturing of hemp fiber reinforced polylactic acid composite honeycomb structures","authors":"Kandy Benié ,&nbsp;Abel Cherouat ,&nbsp;Thierry Barrière ,&nbsp;Vincent Placet","doi":"10.1016/j.addma.2025.104697","DOIUrl":"10.1016/j.addma.2025.104697","url":null,"abstract":"<div><div>This paper focuses on optimizing the additive manufacturing of a hemp/PolyLactic Acid composite honeycomb structure using the pellet-based 3D printing as material extrusion process. Based on the Diffusion, Coalescence, Crystallization (DCC) model recently introduced in the literature, this study proposes an optimization of the process parameters to maximize the compression properties of the printed bio-composite honeycomb structure. During 3D printing, the deposition of new strands tends to change the temperature in the previously printed strands. Using the thermal properties of PLA-hemp bio-composite and printing parameters, the Backward Differentiation Formula implicit method was used for solving the numerical simulation of the heat transfer during the printing of successive layers in order to calculate the temperature distribution and history. The heat transfer process was modeled by the transient heat conduction equation and the boundary conditions. At the end of simulations, the temperatures at the interface of the strands were used from probes positioned at each thermal contact and measuring the average temperature of the interface to calculate the DCC parameter. The mechanical performance of bio-composite PLA/hemp honeycomb structure was evaluated discussed using different machine parameters combinations as extrusion temperature, layer height, flow speed and platform temperature. The obtained results showed that minimizing the layer height while maximizing the extrusion temperature, the build platform temperature and the printing flow speed effectively enhances the compression properties of the structure. Experimental measurements of the axial compressive modulus and strength of the honeycomb structure validated these findings and highlighted the improved interlayer adhesion achieved by employing the best process parameters.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104697"},"PeriodicalIF":10.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing the microstructural and mechanical isotropy for the twin-wire directed energy deposition-arc fabricated Ti-48Al-2Cr-2Nb alloy via interpass remelting","authors":"Danqi Zhang ,&nbsp;Chen Shen ,&nbsp;Lin Wang ,&nbsp;Wenlu Zhou ,&nbsp;Ting Zhang ,&nbsp;Ying Li ,&nbsp;Yuelong Zhang ,&nbsp;Fang Li ,&nbsp;Jianwen Xin ,&nbsp;Kanglong Wu ,&nbsp;Gang Ruan ,&nbsp;Xueming Hua","doi":"10.1016/j.addma.2025.104696","DOIUrl":"10.1016/j.addma.2025.104696","url":null,"abstract":"<div><div>Twin-wire directed energy deposition-arc (TW-DED-arc) has demonstrated feasibility in fabricating TiAl alloys. Unfortunately, it is hard to simultaneously guarantee the effective product utilization, and suppress the anisotropy. To break the trade-offs, a novel depositing strategy of an interpass remelting (IR) process, a representative of low-carbon-friendly and easy-to-operate processing route, is designed to fabricate Ti-48Al-2Cr-2Nb (TiAl-4822) alloy without chemical adjustment. The results indicated that the IR process promoted high-fraction equiaxed grains of ∼90 %, much higher than that fabricated by constant process (CP). The IR process significantly increased the microstructural and mechanical isotropy of TW-DED-arc fabricated TiAl-4822 alloy. For microstructural isotropy, the IR process facilitated the growth of equiaxed grains with appropriate size, twin thickness refinement, and micro-segregation improvement. The IR process also strengthened the α₂/γ phase interface and γ/γ twinning boundaries. For mechanical isotropy, the IR process generated superior tensile properties along different directions of TW-DED-arc fabricated TiAl-4822 alloy wall compared to CP process and other fabricating techniques. Meanwhile, the exceptional strength retention of about 97 % at 650 °C was maintained. This work provides a new perspective to optimize microstructure and mechanical properties of TiAl-4822 alloys, facilitating further development of TW-DED-arc and its application in aerospace industry.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"101 ","pages":"Article 104696"},"PeriodicalIF":10.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of dual conductive networks based on material jetting for high-performance flexible strain sensors","authors":"Gang Chen ,&nbsp;Yang Li ,&nbsp;Pan He ,&nbsp;Yujun Wei ,&nbsp;Jiupeng Song ,&nbsp;Biyou Peng ,&nbsp;Yijun Li","doi":"10.1016/j.addma.2025.104698","DOIUrl":"10.1016/j.addma.2025.104698","url":null,"abstract":"<div><div>Flexible strain sensors convert external mechanical stimuli into corresponding electrical signals, offering broad application prospects in electronic devices. However, achieving both a wide operating range and high sensitivity remains a key challenge. Material jetting (MJ) holds significant potential for sensor fabrication due to its contactless, maskless, and high-resolution printing process. Herein, we developed a flexible strain sensor with dual conductive networks, consisting of a polyvinyl alcohol/multi-walled carbon nanotubes (PVA/MWCNT) substrate layer and an overlying poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/MWCNT (PEDOT:PSS/MWCNT) layer patterned and deposited layer by layer using a typical MJ technology, aerosol jet printing (AJP). Owing to the synergistic effect between the printed circuit and the flexible substrate, the meander-shaped sensor, fabricated under optimized 16-layer printing, achieved a wide strain response range of 0.6–80 % and high sensitivity with a gauge factor (GF) of 31.2. Additionally, the strain sensor stabilized its current signal under 2000 cyclic loading conditions, demonstrating good stability. We further investigated the effect of patterned grid density on sensor sensitivity, finding that sensitivity increased with grid density initially and then decreased, reaching an impressive GF of 47.52 at a grid density of 2 × 6. Furthermore, the sensor demonstrated remarkable versatility in applications such as full-range human body motion detection, Morse code communication, and UAV flight monitoring, including real-time strain detection during takeoff and landing processes. This study highlights the potential of AJP technology for precise patterning and the fabrication of next-generation flexible strain sensors.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104698"},"PeriodicalIF":10.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}