As intelligent wearable devices,they will inevitably be subjected to various damages and disturbances from the external environment during daily use.Therefore,it is urgent to develop safeguarding materials with multip...As intelligent wearable devices,they will inevitably be subjected to various damages and disturbances from the external environment during daily use.Therefore,it is urgent to develop safeguarding materials with multiple protective properties.Herein,this work developed a flexible and breathable three-dimensional(3D)porous shear stiffening elastomer(SSE)/MXene(M-SSE)foam with impact/electromagnetic interference(EMI)/bacteria multiple protection performance for intelligent wearable devices.The continuous conductive MXene network in the 3D SSE porous structure made M-SSE foam exhibit excellent electromagnetic interference shielding property with a high shielding effectiveness of 34 dB.Attributed to the shear stiffening effect of porous SSE matrix,M-SSE foam possessed unique anti-impact and protection properties.The energy dissipation rate reached up to more than 85%,illustrating M-SSE foam could effectively attenuate the external impact force and absorb the impact energy.Inherited from the excellent photothermal performance of MXene,M-SSE foam achieved a considerable saturated temperature of 98℃ under 0.57 W/cm^(2) laser power.Therefore,M-SSE foam showed extraordinary antimicrobial property for Staphylococcus aureus according to the principle of photothermal sterilization.Finally,for the development of intelligent wearable devices,conductive MSSE foam could be used as an intelligent sensor to monitor various human movements owing to the highly sensitive property.This work greatly expanded the application prospect of multifunctional protective materials in various complex environments and promoted the development of multifunctional smart wearable devices in protection field.展开更多
Different from the traditional magnetorheological(MR)fluids and elastomers,the magnetic particles in the plastic MR materials are not‘deadly’trapped in the polymer matrix;thus,the MR plastomers exhibit higher MR eff...Different from the traditional magnetorheological(MR)fluids and elastomers,the magnetic particles in the plastic MR materials are not‘deadly’trapped in the polymer matrix;thus,the MR plastomers exhibit higher MR effects and lower sedimentation.The plastic MR materials have attracted increasing attention,and the relevant fundamental mechanisms and practical applications have been intensively studied due to their unique physical and mechanical properties.In this highlight,we have mainly reviewed the preparation and the rheological properties of the MR plastomers.The formation mechanism of the MR plastomers has also been briefly summarized.展开更多
With the booming development of smart wearable devices,flexible multifunctional composites with high sensitivity and well health therapy have evoked great interest for next-generation healthcare electronics.However,th...With the booming development of smart wearable devices,flexible multifunctional composites with high sensitivity and well health therapy have evoked great interest for next-generation healthcare electronics.However,the weak biocompatibility,low breathability,and narrow sensing range greatly hinder the development of healthcare sensors.Herein,a porous,flexible and conductive MXene/Polydimethylsiloxane/Polydopamine/Polyurethane Sponge(MXene/PDMS/PDA/PU)nanocomposite is developed as a promising motion-detecting device with good flexibility,breathability,sensing performance,photothermal therapy and antibacterial activity.Benefiting from the porous structure and biocompatible surface,this multifunctional sensor is further fabricated into a diagnostic and therapeutic system for monitoring human body motion and performing hot therapy/antibacterial treatment in the application of sports injury site.Moreover,both the wireless smart insole and cushion are constructed to gait monitoring and sit position detecting.This multifunctional hybrid sponge not only demonstrates great potential for motion monitoring sensors but also exhibits wide potential in wearable medical assistive and therapeutic systems.展开更多
In this research, a series of hollow glass powder(HGP) reinforced magnetorheological plastomers(MRPs)were prepared to improve the impact resistance of the materials, and the dynamic compressive properties of MRPs unde...In this research, a series of hollow glass powder(HGP) reinforced magnetorheological plastomers(MRPs)were prepared to improve the impact resistance of the materials, and the dynamic compressive properties of MRPs under high strain rate were investigated by using a split Hopkinson pressure bar(SHPB)system equipped with a customized magnetic device. Experimental results showed the HGPs greatly enhanced the yield stresses of the MRPs. Especially, for MRPs with 9 vol.% carbonyl iron powders(CIPs), the magnetic-induced yield stress increased from 7.3 MPa to 17.1 MPa(134% increased) by adding 18 vol.%HGPs. The particle structures in MRPs were further simulated and the corresponding intergranular stress was calculated to study the enhancement effect of HGPs. The simulated results showed that more compact structures were formed with the excluded volume caused by secondary HGPs, so the yield stresses of the MRPs increased under a magnetic field. However, when the mass ratio of HGP to CIP was larger than 0.67, HGPs would hinder the formation of chain-like structures and reduce the magneto-mechanical properties. As a result, the replacing of CIPs by HGPs was proven to be an excellent strategy to improve the dynamic properties of MRPs.展开更多
Magnetic liquid metal droplets(MLMDs)have been proven to be very important in many fields such as flexible electronics and soft robotics.Usually,soft magnetic particles such as nickel(Ni)and iron(Fe)are mixed or suspe...Magnetic liquid metal droplets(MLMDs)have been proven to be very important in many fields such as flexible electronics and soft robotics.Usually,soft magnetic particles such as nickel(Ni)and iron(Fe)are mixed or suspended into the liquid metal to obtain soft MLMDs(S-LMDs),which can be easily manipulated under the magnetic field due to the favorable deformability and flexibility.In addition,hard magnetic particles such as neodymium iron boron(Nd Fe B)with a high residual magnetization can also be dispersed into the liquid metal and the hard MLMDs(H-LMDs)become more compact due to the interaction between internal particles induced by remanence.This work reports a kind of H-LMDs with high surface tension,high flexibility and mechanical robustness,whose electrical conductivity and strength are better than the S-LMDs.Under the magnetic field,the H-LMDs have a faster response time(0.58 s)and a larger actuating velocity(4.45 cm/s)than the S-LMDs.Moreover,the H-LMDs show excellent magnetic controllability,good elasticity and favorable mobility,as demonstrated by magnetically actuated locomotion,bounce tests and rolling angle measurements.Finally,the droplets can be further applied in wheeldriven motors and micro-valve switches,which demonstrates their high application potential in robotic manipulation and microfluidic devices.展开更多
基金Financial supports from the National Natural Science Foundation of China(Nos.12202435,12132016,11972032,and 12072338)the Fundamental Research Funds for the Central Universities(Nos.WK2480000007 and WK5290000003)China Postdoctoral Science Foundation(No.2021M703086)are gratefully acknowledged.
文摘As intelligent wearable devices,they will inevitably be subjected to various damages and disturbances from the external environment during daily use.Therefore,it is urgent to develop safeguarding materials with multiple protective properties.Herein,this work developed a flexible and breathable three-dimensional(3D)porous shear stiffening elastomer(SSE)/MXene(M-SSE)foam with impact/electromagnetic interference(EMI)/bacteria multiple protection performance for intelligent wearable devices.The continuous conductive MXene network in the 3D SSE porous structure made M-SSE foam exhibit excellent electromagnetic interference shielding property with a high shielding effectiveness of 34 dB.Attributed to the shear stiffening effect of porous SSE matrix,M-SSE foam possessed unique anti-impact and protection properties.The energy dissipation rate reached up to more than 85%,illustrating M-SSE foam could effectively attenuate the external impact force and absorb the impact energy.Inherited from the excellent photothermal performance of MXene,M-SSE foam achieved a considerable saturated temperature of 98℃ under 0.57 W/cm^(2) laser power.Therefore,M-SSE foam showed extraordinary antimicrobial property for Staphylococcus aureus according to the principle of photothermal sterilization.Finally,for the development of intelligent wearable devices,conductive MSSE foam could be used as an intelligent sensor to monitor various human movements owing to the highly sensitive property.This work greatly expanded the application prospect of multifunctional protective materials in various complex environments and promoted the development of multifunctional smart wearable devices in protection field.
基金supported by the Collaborative Innovation Center of Suzhou Nano Science and Technology.Financial support from the National Natural Science Foundation of China[grant number 11372301],[grant number 11125210]the Anhui Provincial Natural Science Foundation of China[grant number 1408085QA17]the National Basic Research Program of China(973 Program)[grant number 2012CB937500]is gratefully acknowledged.
文摘Different from the traditional magnetorheological(MR)fluids and elastomers,the magnetic particles in the plastic MR materials are not‘deadly’trapped in the polymer matrix;thus,the MR plastomers exhibit higher MR effects and lower sedimentation.The plastic MR materials have attracted increasing attention,and the relevant fundamental mechanisms and practical applications have been intensively studied due to their unique physical and mechanical properties.In this highlight,we have mainly reviewed the preparation and the rheological properties of the MR plastomers.The formation mechanism of the MR plastomers has also been briefly summarized.
基金National Natural Science Foundation of China (Grant Nos.12072338,11972343,12132016,12202435)the Anhui’s Key R&D Program of China (202104a05020009)+1 种基金the Fundamental Research Funds for the Central Universities (WK2480000007)the Aviation Science Foundation of China (20200029079004),are gratefully acknowledged.
文摘With the booming development of smart wearable devices,flexible multifunctional composites with high sensitivity and well health therapy have evoked great interest for next-generation healthcare electronics.However,the weak biocompatibility,low breathability,and narrow sensing range greatly hinder the development of healthcare sensors.Herein,a porous,flexible and conductive MXene/Polydimethylsiloxane/Polydopamine/Polyurethane Sponge(MXene/PDMS/PDA/PU)nanocomposite is developed as a promising motion-detecting device with good flexibility,breathability,sensing performance,photothermal therapy and antibacterial activity.Benefiting from the porous structure and biocompatible surface,this multifunctional sensor is further fabricated into a diagnostic and therapeutic system for monitoring human body motion and performing hot therapy/antibacterial treatment in the application of sports injury site.Moreover,both the wireless smart insole and cushion are constructed to gait monitoring and sit position detecting.This multifunctional hybrid sponge not only demonstrates great potential for motion monitoring sensors but also exhibits wide potential in wearable medical assistive and therapeutic systems.
基金financially supported by the National Natural Science Foundation of China (Nos. 12102424, 12132016, 11972343, and 11822209)the National Key R&D Program of China (No. 2018YFB1201703)+1 种基金the Anhui’s Key R&D Program of China (No. 202104a05020009)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB22040502)。
文摘In this research, a series of hollow glass powder(HGP) reinforced magnetorheological plastomers(MRPs)were prepared to improve the impact resistance of the materials, and the dynamic compressive properties of MRPs under high strain rate were investigated by using a split Hopkinson pressure bar(SHPB)system equipped with a customized magnetic device. Experimental results showed the HGPs greatly enhanced the yield stresses of the MRPs. Especially, for MRPs with 9 vol.% carbonyl iron powders(CIPs), the magnetic-induced yield stress increased from 7.3 MPa to 17.1 MPa(134% increased) by adding 18 vol.%HGPs. The particle structures in MRPs were further simulated and the corresponding intergranular stress was calculated to study the enhancement effect of HGPs. The simulated results showed that more compact structures were formed with the excluded volume caused by secondary HGPs, so the yield stresses of the MRPs increased under a magnetic field. However, when the mass ratio of HGP to CIP was larger than 0.67, HGPs would hinder the formation of chain-like structures and reduce the magneto-mechanical properties. As a result, the replacing of CIPs by HGPs was proven to be an excellent strategy to improve the dynamic properties of MRPs.
基金Financial support from the National Natural Science Foundation of China(Grant Nos.11822209,12072338,11772320)the Fundamental Research Funds for the Central Universities(WK2480000007)+2 种基金Joint Fund of USTC-National Synchrotron Radiation Laboratory(KY2090000055)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB22040502)Thanks to the instrumentation support from engineering practice center of USTC。
文摘Magnetic liquid metal droplets(MLMDs)have been proven to be very important in many fields such as flexible electronics and soft robotics.Usually,soft magnetic particles such as nickel(Ni)and iron(Fe)are mixed or suspended into the liquid metal to obtain soft MLMDs(S-LMDs),which can be easily manipulated under the magnetic field due to the favorable deformability and flexibility.In addition,hard magnetic particles such as neodymium iron boron(Nd Fe B)with a high residual magnetization can also be dispersed into the liquid metal and the hard MLMDs(H-LMDs)become more compact due to the interaction between internal particles induced by remanence.This work reports a kind of H-LMDs with high surface tension,high flexibility and mechanical robustness,whose electrical conductivity and strength are better than the S-LMDs.Under the magnetic field,the H-LMDs have a faster response time(0.58 s)and a larger actuating velocity(4.45 cm/s)than the S-LMDs.Moreover,the H-LMDs show excellent magnetic controllability,good elasticity and favorable mobility,as demonstrated by magnetically actuated locomotion,bounce tests and rolling angle measurements.Finally,the droplets can be further applied in wheeldriven motors and micro-valve switches,which demonstrates their high application potential in robotic manipulation and microfluidic devices.
