Once China’s Tianwen-1 Mars probe arrived in a Mars orbit after a seven-month flight in the deep cold space environment,it would be urgently necessary to monitor its state and the surrounding environment.To address t...Once China’s Tianwen-1 Mars probe arrived in a Mars orbit after a seven-month flight in the deep cold space environment,it would be urgently necessary to monitor its state and the surrounding environment.To address this issue,we developed a flexible deployable subsystem based on shape memory polymer composites(SMPC-FDS)with a large folding ratio,which incorporates a camera and two temperature telemetry points for monitoring the local state of the Mars orbiter and the deep space environment.Here,we report on the development,testing,and successful application of the SMPC-FDS.Before reaching its Mars remote-sensing orbit,the SMPC-FDS is designed to be in a folded state with high stiffness;after reaching orbit,it is in a deployed state with a large envelope.The transition from the folded state to the deployed state is achieved by electrically heating the shape memory polymer composites(SMPCs);during this process,the camera on the SMPC-FDS can capture the local state of the orbiter from multiple angles.Moreover,temperature telemetry points on the SMPC-FDS provide feedback on the environment temperature and the temperature change of the SMPCs during the energization process.By simulating a Mars on-orbit space environment,the engineering reliability of the SMPC-FDS was comprehensively verified in terms of the material properties,structural dynamic performance,and thermal vacuum deployment feasibility.Since the launch of Tianwen-1 on 23 July 2020,scientific data on the temperature environment around Tianwen-1 has been successfully acquired from the telemetry points on the SMPCFDS,and the local state of the orbiter has been photographed in orbit,showing the national flag of China fixed on the orbiter.展开更多
The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical exp...The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical expressions for the meso-displacement field, stressstrain field of typical element with damage were presented, and a failure criterion for interface failure between SMA wires and matrix was established under two kinds of actuation which are dead-load and temperature, where the temperature is included in effective free restoring strain. In addition, there are some other composing factors in the failure criterion such as the interface properties, dynamical properties of SMA, initial debonding length L - l etc. The results are significant to understand structural strength self-adapted control and failure mechanism of SMA wires reinforced smart structure with damage.展开更多
Shape memory polymer composites(SMPCs)are a type of smart material that can change shapes under the stimulation of the external environment,and they have great potential in aerospace,biomedical,robotics,and electronic...Shape memory polymer composites(SMPCs)are a type of smart material that can change shapes under the stimulation of the external environment,and they have great potential in aerospace,biomedical,robotics,and electronic devices due to their advantages of high strength and toughness,lightweight,impact resistance,corrosion resistance,and aging resistance.4D printing technology has provided new opportunities for the further development of smart materials.The addition of various fillers enriches the variety of printable materials and provides composites with different properties and functions.The combination of SMPCs and printing technologies realizes the structure-function integration.This paper introduces the emergence and development of 4D printing technologies,the preparation methods and properties of SMPCs for 4D printing;as well as the research progress and potential application of 4D printable SMPCs in recent years in terms of thermal,electrical,magnetic,and optical driving.Finally,the existing problems and future development of 4D printable SMPCs are discussed.展开更多
The properties of functionally graded(FG) cellular structures vary spatially, and the varying properties can meet the requirements of different working environments. In this study, we fabricated FG cellular structures...The properties of functionally graded(FG) cellular structures vary spatially, and the varying properties can meet the requirements of different working environments. In this study, we fabricated FG cellular structures with shape memory effect by 4D printing and evaluated the compressive performance and shape memory behavior of these structures with temperature through experimental analysis and finite element simulations. The results show that the maximum energy absorption gradually decreases but the compressive modulus gradually increases with increasing gradient parameters. Moreover, the finite element simulations also show that the compressive deformation mode of the structure shifts from uniform to non-uniform deformation with increasing gradient parameters. The compressive modulus and compressive strength of 4D printed FG structures decrease with increasing temperature due to the influence of the shape memory polymer, and they exhibit outstanding shape recovery capability under high-temperature stimulus. The proposed 4D printed FG structures with such responsiveness to stimulus shed light on the design of intelligent energy-absorbing devices that meet specific functional requirements.展开更多
Shape memory polymers are smart materials that produce shape changes under external stimulus conditions.Four-dimensional(4D)printing is a comprehensive technology originate from deformable materials and three-dimensio...Shape memory polymers are smart materials that produce shape changes under external stimulus conditions.Four-dimensional(4D)printing is a comprehensive technology originate from deformable materials and three-dimensional(3D)printing technology.At present,4D printed shape memory polymers and shape-changing structures have been applied in various fields,especially in the field of biomedical science.4D printing technology has made a breakthrough of personalized customization in the traditional medical field,providing a new direction for the further development of the biomedical field.In this review,the recent research and development of shape memory polymer,3D printing technology,4D printed shape memory polymers and shape-changing structures in biomedical area are present.The examples and applications of 4D printed shape memory polymers and their structures in the area of biomedical are also introduced.Based on 4D printing,stimulated by different conditions,3D printed objects can be fabricated into various biomedical applications such as cell scaffolds,vascular stents,bone scaffolds,tracheal stents and cardiac stents by different 3D printing techniques.Finally,the application prospects,existing technical restriction and future development directions of 4D printed shape memory polymers and their structures in the biomedical field are summarized.展开更多
The deployable structures based on shape memory polymer com-posites(SMPCs)have been developed for its unique properties,such as high reliability,low-cost,lightweight,and self-deployment without complex mechanical devi...The deployable structures based on shape memory polymer com-posites(SMPCs)have been developed for its unique properties,such as high reliability,low-cost,lightweight,and self-deployment without complex mechanical devices compared with traditional deployable structures.In order to increase the inflatable structure system’s robustness and light the weight of it,a cubic deployable support structure based on SMPC is designed and analyzed pre-liminarily.The cubic deployable support structure based on SMPC consists of four dependent spatial cages,each spatial cage is composed of 12 three-longeron SMPC truss booms and end con-nections.The shape recovery of arc-shaped deployable laminates drive the three-longeron SMPC truss booms to unfold,thus realize the expansion of the deployable support structure.The concept and operation of the cubic deployable support structure are described in detail.A series of experiments are performed on the three-longeron deployable laminates unit and the simplified cubic deployable support structure to investigate the shape recovery behavior in the deployment process.Results indicate that the cubic deployable support structure has a high deployment-tgo-stowage volume ratio and can achieve self-deployment,package,and deploy without complex mechanical devices.展开更多
Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-d...Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-dioxanone)(PPDO)materials were incorporated to improve the brittleness of shape memory polylactic acid(PLA),and plasticizers were used to reduce the transition temperature of SMP composites such that their transitions could be induced close to body temperature.Furthermore,an electrostatic spinning technology was applied to prepare SMP fibers with wrinkled structures and regulate their microstructures and morphologies such that the intelligent transition of wrinkled and smooth morphologies can be achieved on the fiber surface.The application of this controllable-morphology fiber membrane in intelligent controlled drug release and scar inhibition after Ahmed Glaucoma Valve(AGV)implantation was also studied.The drug release from the stretched and deformed drug-loaded fiber membranes was faster than those from membranes with the original shape.This membrane with micro-and nano-fibers had good anti-scarring effects that improved after drug loading.The achievement of intelligent controlled drug release and the evident anti-scarring effects of the membrane broaden the application of SMP fibers in the biomedical field.展开更多
In this paper, to meet the environmental requirements for the lunar surface, we outline the design of an intelligent shape memory polymer(SMP) capsule structure of lightweight using a flexible composite skin. Key brea...In this paper, to meet the environmental requirements for the lunar surface, we outline the design of an intelligent shape memory polymer(SMP) capsule structure of lightweight using a flexible composite skin. Key breakthrough technology for manufacturing the high-performance multilayer composite is utilized to realize the requirements for folding and compressing during launching, and unfolding on the lunar surface, taking into account the current opposing requirements for launching and the space transportation mission of large equipment. Based upon the reduced constraints, better expansibility and easy assembly, this lunar base is suited to the initial and interim phases of a moon construction, and provides a national solution in the construction of lunar base on moon.展开更多
In this work, hybrid conductive fillers of carbon black (CB) and carbon nanotubes (CNTs) were introduced into polylactide (PLA)/thermoplastic poly(ether)urethane (TPU) blend (70/30 by weight) to tune the p...In this work, hybrid conductive fillers of carbon black (CB) and carbon nanotubes (CNTs) were introduced into polylactide (PLA)/thermoplastic poly(ether)urethane (TPU) blend (70/30 by weight) to tune the phase morphology and realize rapid electrically actuated shape memory effect (SME). Particularly, the dispersion of conductive fillers, the phase morphology, the electrical conductivities and the shape memory properties of the composites containing CB or CB/CNTs were comparatively investigated. The results suggested that both CB and CNTs were selectively localized in TPU phase, and induced the morphological change from the sea-island structure to the co-continuous structure. The presence of CNTs resulted in a denser CB/CNTs network, which enhanced the continuity of TPU phase. Because the formed continuous TPU phase provided stronger recovery driving force, the PLA/TPU/CB/CNTs composites showed better shape recovery properties compared with the PLA/TPU/CB composites at the same CB content. Moreover, the CB and CNTs exerted a synergistic effect on enhancing the electrical conduetivities of the composites. As a result, the prepared composites exhibited excellent electrically actuated SME and the shape recovery speed was also greatly enhanced. This work demonstrated a promising strategy to achieve rapid electrically actuated SME via the addition of hybrid nanoparticles with self-networking ability in binary PLA/TPU blends over a much larger composition range.展开更多
基金supported by the National Natural Science Foundation of China(11632005)the Heilongjiang Touyan Innovation Team Program。
文摘Once China’s Tianwen-1 Mars probe arrived in a Mars orbit after a seven-month flight in the deep cold space environment,it would be urgently necessary to monitor its state and the surrounding environment.To address this issue,we developed a flexible deployable subsystem based on shape memory polymer composites(SMPC-FDS)with a large folding ratio,which incorporates a camera and two temperature telemetry points for monitoring the local state of the Mars orbiter and the deep space environment.Here,we report on the development,testing,and successful application of the SMPC-FDS.Before reaching its Mars remote-sensing orbit,the SMPC-FDS is designed to be in a folded state with high stiffness;after reaching orbit,it is in a deployed state with a large envelope.The transition from the folded state to the deployed state is achieved by electrically heating the shape memory polymer composites(SMPCs);during this process,the camera on the SMPC-FDS can capture the local state of the orbiter from multiple angles.Moreover,temperature telemetry points on the SMPC-FDS provide feedback on the environment temperature and the temperature change of the SMPCs during the energization process.By simulating a Mars on-orbit space environment,the engineering reliability of the SMPC-FDS was comprehensively verified in terms of the material properties,structural dynamic performance,and thermal vacuum deployment feasibility.Since the launch of Tianwen-1 on 23 July 2020,scientific data on the temperature environment around Tianwen-1 has been successfully acquired from the telemetry points on the SMPCFDS,and the local state of the orbiter has been photographed in orbit,showing the national flag of China fixed on the orbiter.
基金Project partially supported by the Aeronautical Science Foundation of China (No. 05G52054).
文摘The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical expressions for the meso-displacement field, stressstrain field of typical element with damage were presented, and a failure criterion for interface failure between SMA wires and matrix was established under two kinds of actuation which are dead-load and temperature, where the temperature is included in effective free restoring strain. In addition, there are some other composing factors in the failure criterion such as the interface properties, dynamical properties of SMA, initial debonding length L - l etc. The results are significant to understand structural strength self-adapted control and failure mechanism of SMA wires reinforced smart structure with damage.
基金supported by the National Natural Science Foundation of China(Grant No.11632005)the Heilongjiang Touyan Innovation Team Program。
文摘Shape memory polymer composites(SMPCs)are a type of smart material that can change shapes under the stimulation of the external environment,and they have great potential in aerospace,biomedical,robotics,and electronic devices due to their advantages of high strength and toughness,lightweight,impact resistance,corrosion resistance,and aging resistance.4D printing technology has provided new opportunities for the further development of smart materials.The addition of various fillers enriches the variety of printable materials and provides composites with different properties and functions.The combination of SMPCs and printing technologies realizes the structure-function integration.This paper introduces the emergence and development of 4D printing technologies,the preparation methods and properties of SMPCs for 4D printing;as well as the research progress and potential application of 4D printable SMPCs in recent years in terms of thermal,electrical,magnetic,and optical driving.Finally,the existing problems and future development of 4D printable SMPCs are discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos.12072094 and 12172106)。
文摘The properties of functionally graded(FG) cellular structures vary spatially, and the varying properties can meet the requirements of different working environments. In this study, we fabricated FG cellular structures with shape memory effect by 4D printing and evaluated the compressive performance and shape memory behavior of these structures with temperature through experimental analysis and finite element simulations. The results show that the maximum energy absorption gradually decreases but the compressive modulus gradually increases with increasing gradient parameters. Moreover, the finite element simulations also show that the compressive deformation mode of the structure shifts from uniform to non-uniform deformation with increasing gradient parameters. The compressive modulus and compressive strength of 4D printed FG structures decrease with increasing temperature due to the influence of the shape memory polymer, and they exhibit outstanding shape recovery capability under high-temperature stimulus. The proposed 4D printed FG structures with such responsiveness to stimulus shed light on the design of intelligent energy-absorbing devices that meet specific functional requirements.
基金supported by the National Natural Science Foundation of China(Grant Nos.11632005,11672086&11802075)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.11421091)the China Postdoctoral Science Foundation Funded Project。
文摘Shape memory polymers are smart materials that produce shape changes under external stimulus conditions.Four-dimensional(4D)printing is a comprehensive technology originate from deformable materials and three-dimensional(3D)printing technology.At present,4D printed shape memory polymers and shape-changing structures have been applied in various fields,especially in the field of biomedical science.4D printing technology has made a breakthrough of personalized customization in the traditional medical field,providing a new direction for the further development of the biomedical field.In this review,the recent research and development of shape memory polymer,3D printing technology,4D printed shape memory polymers and shape-changing structures in biomedical area are present.The examples and applications of 4D printed shape memory polymers and their structures in the area of biomedical are also introduced.Based on 4D printing,stimulated by different conditions,3D printed objects can be fabricated into various biomedical applications such as cell scaffolds,vascular stents,bone scaffolds,tracheal stents and cardiac stents by different 3D printing techniques.Finally,the application prospects,existing technical restriction and future development directions of 4D printed shape memory polymers and their structures in the biomedical field are summarized.
基金This work is supported by the National Natural Science Foundation of China(Grant No.11225211,No.11272106,No.11102052).
文摘The deployable structures based on shape memory polymer com-posites(SMPCs)have been developed for its unique properties,such as high reliability,low-cost,lightweight,and self-deployment without complex mechanical devices compared with traditional deployable structures.In order to increase the inflatable structure system’s robustness and light the weight of it,a cubic deployable support structure based on SMPC is designed and analyzed pre-liminarily.The cubic deployable support structure based on SMPC consists of four dependent spatial cages,each spatial cage is composed of 12 three-longeron SMPC truss booms and end con-nections.The shape recovery of arc-shaped deployable laminates drive the three-longeron SMPC truss booms to unfold,thus realize the expansion of the deployable support structure.The concept and operation of the cubic deployable support structure are described in detail.A series of experiments are performed on the three-longeron deployable laminates unit and the simplified cubic deployable support structure to investigate the shape recovery behavior in the deployment process.Results indicate that the cubic deployable support structure has a high deployment-tgo-stowage volume ratio and can achieve self-deployment,package,and deploy without complex mechanical devices.
基金supported by the National Natural Science Foundation of China(Grant No.11802075,12072094,81870654,and 82070956)the Fundamental Research Funds for the Central Universities(No.IR2021106 and IR2021232)Applied Technology Research and Development Program of Heilongjiang Provincial Science and Technology Department(GA20C008).
文摘Micro-and nano-fibers of shape memory polymers(SMP)offer multiple advantages like high specific surface area,poros-ity,and intelligence,and are suitable for biomedical applications.In this study,biodegradable poly(p-dioxanone)(PPDO)materials were incorporated to improve the brittleness of shape memory polylactic acid(PLA),and plasticizers were used to reduce the transition temperature of SMP composites such that their transitions could be induced close to body temperature.Furthermore,an electrostatic spinning technology was applied to prepare SMP fibers with wrinkled structures and regulate their microstructures and morphologies such that the intelligent transition of wrinkled and smooth morphologies can be achieved on the fiber surface.The application of this controllable-morphology fiber membrane in intelligent controlled drug release and scar inhibition after Ahmed Glaucoma Valve(AGV)implantation was also studied.The drug release from the stretched and deformed drug-loaded fiber membranes was faster than those from membranes with the original shape.This membrane with micro-and nano-fibers had good anti-scarring effects that improved after drug loading.The achievement of intelligent controlled drug release and the evident anti-scarring effects of the membrane broaden the application of SMP fibers in the biomedical field.
基金supported by Natural Science Foundation of China, 51603123
文摘In this paper, to meet the environmental requirements for the lunar surface, we outline the design of an intelligent shape memory polymer(SMP) capsule structure of lightweight using a flexible composite skin. Key breakthrough technology for manufacturing the high-performance multilayer composite is utilized to realize the requirements for folding and compressing during launching, and unfolding on the lunar surface, taking into account the current opposing requirements for launching and the space transportation mission of large equipment. Based upon the reduced constraints, better expansibility and easy assembly, this lunar base is suited to the initial and interim phases of a moon construction, and provides a national solution in the construction of lunar base on moon.
基金financially supported by the National Natural Science Foundation of China(Nos.51421061 and 51210005)
文摘In this work, hybrid conductive fillers of carbon black (CB) and carbon nanotubes (CNTs) were introduced into polylactide (PLA)/thermoplastic poly(ether)urethane (TPU) blend (70/30 by weight) to tune the phase morphology and realize rapid electrically actuated shape memory effect (SME). Particularly, the dispersion of conductive fillers, the phase morphology, the electrical conductivities and the shape memory properties of the composites containing CB or CB/CNTs were comparatively investigated. The results suggested that both CB and CNTs were selectively localized in TPU phase, and induced the morphological change from the sea-island structure to the co-continuous structure. The presence of CNTs resulted in a denser CB/CNTs network, which enhanced the continuity of TPU phase. Because the formed continuous TPU phase provided stronger recovery driving force, the PLA/TPU/CB/CNTs composites showed better shape recovery properties compared with the PLA/TPU/CB composites at the same CB content. Moreover, the CB and CNTs exerted a synergistic effect on enhancing the electrical conduetivities of the composites. As a result, the prepared composites exhibited excellent electrically actuated SME and the shape recovery speed was also greatly enhanced. This work demonstrated a promising strategy to achieve rapid electrically actuated SME via the addition of hybrid nanoparticles with self-networking ability in binary PLA/TPU blends over a much larger composition range.