Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into the...Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into their periodic interconnect configurations,resulting in their lack of modularity,scalable fabrication,and programmability.Mechanical metamaterials typically exhibit a single extraordinary mechanical property or multiple extraordinary properties coupled together,making it difficult to realize multiple independent extraordinary mechanical properties.Here,the pixel mechanics metamaterials(PMMs)with multifunctional and reprogrammable properties are developed by arraying uncoupled constrained individual modular mechanics pixels(MPs).The MPs enable controlled conversion between two extraordinary mechanical properties(multistability and compression-torsion coupling deformation).Each MP exhibits 32 independent and reversible room temperature programming configurations.In addition,the programmability of metamaterials is further enhanced by shape memory polymer(SMP)and 4D printing,greatly enriching the design freedom.For the PMM consisting of m×n MPs,it has 32(m×n)independent room temperature programming configurations.The application prospects of metamaterials in the vibration isolation device and energy absorption device with programmable performance have been demonstrated.The vibration isolation frequencies of the MP before and after programming were[0 Hz-5.86 Hz],[0 Hz-13.67 Hz and 306.64 Hz-365.23 Hz].The total energy absorption of the developed PMM can be adjusted controllably in the range of 1.01 J-3.91 J.Six standard digital logic gates that do not require sustained external force are designed by controlling the closure between the modules.This design paradigm will facilitate the further development of multifunctional and reprogrammable metamaterials.展开更多
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
基金the financial support provided by the National Key R&D Program of China(2022YFB3805700)the National Natural Science Foundation of China(Grant Nos.12072094 and 12172106)+2 种基金the China Postdoctoral Science Foundation(Grant No.2023M730869)the Heilongjiang Natural Science Foundation Joint Guidance Project(Grant No.LH2023A004)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20230959)。
文摘Metamaterials have exotic physical properties that rely on the construction of their underlying architecture.However,the physical properties of conventional mechanical metamaterials are permanently programmed into their periodic interconnect configurations,resulting in their lack of modularity,scalable fabrication,and programmability.Mechanical metamaterials typically exhibit a single extraordinary mechanical property or multiple extraordinary properties coupled together,making it difficult to realize multiple independent extraordinary mechanical properties.Here,the pixel mechanics metamaterials(PMMs)with multifunctional and reprogrammable properties are developed by arraying uncoupled constrained individual modular mechanics pixels(MPs).The MPs enable controlled conversion between two extraordinary mechanical properties(multistability and compression-torsion coupling deformation).Each MP exhibits 32 independent and reversible room temperature programming configurations.In addition,the programmability of metamaterials is further enhanced by shape memory polymer(SMP)and 4D printing,greatly enriching the design freedom.For the PMM consisting of m×n MPs,it has 32(m×n)independent room temperature programming configurations.The application prospects of metamaterials in the vibration isolation device and energy absorption device with programmable performance have been demonstrated.The vibration isolation frequencies of the MP before and after programming were[0 Hz-5.86 Hz],[0 Hz-13.67 Hz and 306.64 Hz-365.23 Hz].The total energy absorption of the developed PMM can be adjusted controllably in the range of 1.01 J-3.91 J.Six standard digital logic gates that do not require sustained external force are designed by controlling the closure between the modules.This design paradigm will facilitate the further development of multifunctional and reprogrammable metamaterials.
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.
