Article
Materials Science, Multidisciplinary
Charles Abdol-Hamid Owens, Yueping Wang, Shiva Farzinazar, Chen Yang, Howon Lee, Jaeho Lee
Summary: In this study, the authors propose an active thermal control system using 4D-printed shape memory polymers and demonstrate how distinct deformation mechanisms lead to adjustable thermal properties. The findings show that by adjusting strain, the shape and conductance of the material can be changed, providing new insights for tunable thermal systems.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Xiaozhou Xin, Liwu Liu, Yanju Liu, Jinsong Leng
Summary: The study introduces mechanical pixel array design, helical microstructure, and 4D printing technology to enhance the deformation potential of TTCM, leading to the development of pixel mechanical metamaterial. The new material exhibits tunability, programmability, and reconfigurability, and can be utilized in various applications such as information encryption and soft robots.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Mechanics
Mengqi Wan, Keqin Yu, Huiyu Sun
Summary: The paper introduces three kinds of 4D printed programmable metamaterials, whose mechanical properties under different topological angles and radii are studied through experiments and finite element analysis. The results show that these metamaterials can achieve large deformation and auxetic behavior, and the Poisson's ratios and elastic moduli can be programmed by tuning parameters and temperature. Additionally, the proposed cylindrical shells with desired mechanical properties demonstrate potential applications in biomedical scaffolds.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Mechanical
Mengqi Wan, Keqin Yu, Jianping Gu, Hao Zeng, Huiyu Sun, Akbar A. Khatibi
Summary: 4D printing is used to develop Tachi-Miura Polyhedron (TMP) origami metamaterials with reconfigurable shapes and programmable mechanical properties. The TMP origami structures can achieve negative Poisson's ratios and switch between monostable and bistable states. By controlling temperature and adjusting structural parameters, shape memory effects can be programmed to achieve desired deformation shapes and mechanical properties. The 4D printed origami metamaterials offer practical solutions in various engineering applications such as self-deployable structures, energy absorption devices, and flexible electronics.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Polymer Science
Janhavi Sonatkar, Balasubramanian Kandasubramanian, Sikiru Oluwarotimi Ismail
Summary: This study focuses on the application of 3D and 4D printing techniques in biomedical technology. By using intelligent materials and 4D printing methods, dynamic 3D structures can be created, providing further improvements in the healthcare sector.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Chemistry, Physical
Wei Zhao, Nan Li, Xu Liu, Liwu Liu, Chengbin Yue, Chengjun Zeng, Yanju Liu, Jinsong Leng
Summary: This study proposes a novel design strategy for 4D printed metamaterials with programmable stiffness, based on the origami concept. The design strategy is verified through numerical simulation, theoretical analysis, and experimental tests, significantly improving mechanical programmability, shape reconfigurability, and adaptability of the structure. The 4D printed shape memory metamaterials show extraordinary potential in the field of programmable shock absorption and intelligent monitoring.
Article
Chemistry, Multidisciplinary
Devin J. Roach, Xiaohao Sun, Xirui Peng, Frederic Demoly, Kun Zhou, Hang Jerry Qi
Summary: In this study, a LCE-SMP composite was created using 4D printing technology, which enables rapid and reversible shape changes and tunable shape morphing regulated by cooling rate. The composite has a high stiffness at low temperature to support heavy loads, offering a novel approach for future engineering applications.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Sebastian Gonzalez, Emir Chacra, Claudio Carreno, Carolina Espinoza
Summary: One of the biggest challenges in guitar-making is ensuring consistency in sound despite material variations. This study explores the use of wood-based mechanical metamaterials in the design of guitar tops, specifically examining the effect of different hole patterns on the mechanical parameters of Engelman Spruce. The research demonstrates the potential for controlling the elastic properties of perforated wood boards, not only for guitar making but also for various other purposes.
MATERIALS & DESIGN
(2022)
Article
Mechanics
Wei Zhao, Chengbin Yue, Liwu Liu, Jinsong Leng, Yanju Liu
Summary: This study designs and fabricates a series of tension-dominated mechanical metamaterials that can absorb immense amounts of energy while maintaining a low density. The mechanical properties can be adjusted by combining biomimicry and network construction. Additionally, the metamaterials fabricated by 4D printing technology exhibit intelligent properties and self-healing capabilities.
COMPOSITE STRUCTURES
(2023)
Article
Polymer Science
Yuting Zhou, Luquan Ren, Jianfeng Zang, Zhihui Zhang
Summary: Shape-memory polymers have important applications in the fields of mechanism and biomedical engineering, but their use in harsh environments is still challenging. Research has found that polyether-ether-ketone with high glass transition temperature exhibits excellent high-temperature resistance and shape memory behavior. By studying its shape-memory properties and actuation performance, the potential of this polymer in aerospace has been demonstrated.
Article
Materials Science, Composites
Yuting Zhou, Youzhou Yang, Aijia Jian, Tianruo Zhou, Guangming Tao, Luquan Ren, Jianfeng Zang, Zhihui Zhang
Summary: This study presents a co-extrusion 4D printing strategy that integrates continuous metallic fibers into thermoplastic SMP, enabling programmable high-speed heating and deformation. The results demonstrate great potential for expanding the applications of shape memory polymers.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Polymer Science
Aamir Ahmed, Sandeep Arya, Vinay Gupta, Hidemitsu Furukawa, Ajit Khosla
Summary: 4D printing is a technology that allows devices or objects to transform between different dimensions, offering adaptability and new possibilities for manufacturing. Research on materials and applications can help overcome challenges and further develop this innovative technology.
Article
Chemistry, Physical
Zhuo Wang, Yao Zhang, Yanhui Niu, Xuejian Chen, Jianrong Song
Summary: Reports have highlighted the importance of developing high-performance thermal management techniques with low energy consumption, as almost 50% of energy used in buildings is devoted to heating and cooling. In this study, an intelligent shape memory polymers (SMPs)-based device with programmable anisotropic thermal conductivity was developed using 4D printing, to assist in thermal management with net zero energy. Through 3D printing, highly thermal conductive BN nanosheets were incorporated in a PLA matrix, resulting in composites with significant anisotropic thermal conductivity. The programmable movement of the device, including the switching of heat flow direction, was achieved through light-activated deformation controlled by the grayscale of the composite.
Article
Materials Science, Multidisciplinary
Yang Liu, Fenghua Zhang, Jinsong Leng, Tsu-Wei Chou
Summary: This study investigated the tunable shape recovery behavior and recovery force of 4D printed laminated strips based on microstructural design, with results showing significant influence of microstructural parameters on shape recovery behavior and force. The sequential shape-morphing behavior of 4D printed laminated strips using a single material was also demonstrated.
Article
Engineering, Manufacturing
Ijaz Akbar, Mourad El Hadrouz, Mohamed El Mansori, Dimitri Lagoudas
Summary: This study aims to optimize the process of 4D printing SMP through experiments and numerical simulations, reducing defects such as warpage and successfully printing SMPs. The results indicate that the optimized design space can significantly reduce warpage, residual stresses, build, and simulation time, with error percentage results showing good agreement with actual deviations.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Acoustics
Shitong Fang, Mohammad Javad Mirzaei, Mostafa Asadollahi, Keyu Chen, Wei-Hsin Liao
Summary: This study proposes a continuous finite-time terminal sliding mode control method to synchronize two bistable electromechanical transducers. Numerical simulations demonstrate the effectiveness of the proposed control method and interesting findings are discussed for the varying system responses and control inputs in different oscillation modes.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Acoustics
Masoud Rezaei, Roohollah Talebitooti, Wei-Hsin Liao, Michael Friswell
Summary: This paper investigates the potential of a tuned mass damper (TMD) with an integrated piezoelectric layer for simultaneous energy harvesting and vibration suppression. A linear model is validated and analyzed to prepare for future studies on a nonlinear vibration absorber and energy harvester.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Materials Science, Multidisciplinary
Mahmoud Moradi, Mohammadreza Lalegani Dezaki, Erfan Kheyri, Seyyed Alireza Rasouli, Milad Aghaee Attar, Mahdi Bodaghi
Summary: This study investigates the influence of simultaneous magnetization on the magneto-mechanical performance of 4D-printed active polymers. The results show that printed samples with magnets around the printing area have higher magnetic characteristics compared to samples printed with magnets under the printing area and without a magnetic field. The strength also increases when a magnetic field is present and the sample is printed at 0 degrees angle along the tension direction. Therefore, the optimal printing mode for obtaining the appropriate magnetic and mechanical characteristics is 4D printing with magnets under the printing bed at 0 degrees angle along the tension direction.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Iman Sahafnejad-Mohammadi, Sadegh Rahmati, Najmeh Najmoddin, Mahdi Bodaghi
Summary: Previous studies have failed to mimic the gradient structure of natural bone in the design of bone scaffolds. In this study, a biomimetic bone scaffold with Haversian channels was designed to approximate the native bone structure. The influence of incorporating graphene oxide (GO) into polycaprolactone (PCL)-based scaffolds was investigated, and it was found that the addition of GO affected the mechanical properties and biodegradation rates of the scaffolds. Furthermore, cell viability was enhanced in the PCL/GO scaffolds compared to pure PCL scaffolds.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Biotechnology & Applied Microbiology
Huan Zhao, Junyi Cao, Wei-Hsin Liao
Summary: A multi-mass-spring model is established to describe the characteristics of vertical vibration during human walking. The vertical displacements of joints are found to be related to leg length and walking cadence, while the ground reaction force is related to body weight and walking cadence. A simple and universal model is proposed to estimate the vertical stiffness of knee and hip.
BIOENGINEERING-BASEL
(2023)
Article
Automation & Control Systems
Naser Namvar, Ilya Moloukzadeh, Ali Zolfagharian, Frederic Demoly, Mahdi Bodaghi
Summary: This research aims to enhance the performance of scale-model scooter decks by investigating various architected cellular metamaterial and bio-inspired core structure designs. The functionally graded arrowhead structure is found to have the best bending resistance compared to other structures. The research has the potential to advance scooter core designs and improve the performance and safety of scooters.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Automation & Control Systems
Mohammadreza Lalegani Dezaki, Mahdi Bodaghi
Summary: A novel approach is proposed to encode numerous shapes and forms using magneto-electroactive shape memory polymer composite (SMPC) structures and 4D printing technology. Utilizing this method, multiple stable shapes can be achieved and material waste can be reduced through remote programming.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Ying Zhang, Qinghua Liu, Yaguo Lei, Junyi Cao, Wei-Hsin Liao
Summary: To attenuate low-frequency torsional vibration in high payload occasions, a circular Halbach torsion negative stiffness isolator is proposed to provide high torsional magnetic negative stiffness for low-frequency isolation. The semi-analytical expressions of tangential-tangential coupling and tangential-radial coupling for tile magnets are derived to calculate the magnetic torque and the torsional stiffness of circular magnetic arrays. The proposed circular Halbach isolator has a preferable performance for low frequency torsional isolation, with higher magnetic stiffness than the circular traditional array.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Bao Zhao, Jiahua Wang, Guobiao Hu, Andrea Colombi, Wei-Hsin Liao, Junrui Liang
Summary: Nonlinearity has enabled energy harvesting to advance toward higher power output and broader bandwidth in monostable, bistable, and multistable systems. However, operating in the preferable high-energy orbit (HEO) rather than the low-energy orbit (LEO) for making such advancement has restricted their applications. This paper proposes a self-contained solution for time-sharing orbit jump and energy harvesting using a monostable nonlinear system and a switched-mode bidirectional energy conversion circuit. The proposed solution enhances the practical utility of nonlinear energy harvesting technologies toward engineering applications.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Shitong Fang, Keyu Chen, Zhihui Lai, Shengxi Zhou, Daniil Yurchenko, Wei-Hsin Liao
Summary: To prevent the instability and safety risks of a post-capture spacecraft caused by vibrations and drifting motions, the proposed quadrilateral shape isolation system with an energy harvester is capable of simultaneously achieving broadband vibration isolation and energy harvesting. The operation principle is the energy localization effect, which is demonstrated through system dynamics investigation. Improvement guidelines for the dual performances are proposed based on parametric studies on mass ratios, equivalent stiffness and damping induced by quadrilateral shape structures, and mechanical and electrical parameters of the energy harvester.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Chemistry, Physical
Mohammadreza Lalegani Dezaki, Mahdi Bodaghi
Summary: This article introduces a novel conceptual design of meta-laminar jamming (MLJ) actuators fabricated by 4D printing, which can transition from rigid to soft robots. The MLJ actuators utilize polyurethane shape memory polymer (SMP)-based meta-structure and hot and cold programming with negative air pressure. The advantage of MLJ actuators over conventional LJ actuators is the elimination of continuous negative air pressure stimulation.
Article
Materials Science, Multidisciplinary
Narain Kumar Sivakumar, Sabarinathan Palaniyappan, Santhosh Basavarajappa, Mohamed Ibrahim Hashem, Mahdi Bodaghi, Vignesh Sekar
Summary: This study investigates the physical and mechanical characteristics of honeycomb lattice structures using various material extrusion factors. The results show that factors such as infill density, build orientation, and infill pattern have a significant impact on the physical properties, while layer height and build orientation primarily affect the structural area deviation. Additionally, lattice structures with three walls exhibit slower buckling rates.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Engineering, Mechanical
Guoyuan Xia, Qitao Lu, Mingjing Cai, Xin Li, Daxing Zhang, Congsi Wang, Wei-Hsin Liao
Summary: This paper proposes an adaptive kinetic energy reallocation (AKER) mechanism to stabilize the output power of wearable energy harvesters. The AKER manipulates the kinetic energy transfer to enhance system response, thereby achieving power stability.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Mechanics
Ramin Hamzehei, Mahdi Bodaghi, Nan Wu
Summary: This paper investigates the potential of curvy mechanical metamaterials to enhance fracture toughness through topological design. By introducing local curvy ligaments and using 3D printing, a new lattice metamaterial with multi-stiffness unit cells and multi-step fracture control is created. The results demonstrate improved fracture behavior and energy absorption capacity.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2024)
Article
Engineering, Chemical
Rezgar Hasanzadeh, Peyman Mihankhah, Taher Azdast, Mahdi Bodaghi, Mahmoud Moradi
Summary: Polylactic acid (PLA) is widely used in fused filament fabrication (FFF). However, its narrow processing window and low mechanical properties limit its usefulness. PLA composites have been developed to enhance its properties. This study examines the effect of nozzle temperature, printing speed, and nominal porosity on the impact strength of PLA/iron composites using FFF. Response surface methodology is used to optimize the experimental design. The results show that the nominal porosity has the most significant effect on impact resistance, while the nozzle temperature has the least effect. The lowest nozzle temperature, lowest nominal porosity, and a printing speed of 50 mm/s are found to be the optimal conditions.
POLYMER ENGINEERING AND SCIENCE
(2023)