Gallium-based liquid metals are promising for stretchable electronics and beyond.However,their inherent fluidity and weak structural confinement in conventional films often cause leakage and functional failure under e...Gallium-based liquid metals are promising for stretchable electronics and beyond.However,their inherent fluidity and weak structural confinement in conventional films often cause leakage and functional failure under extreme deformation.Here,we report ultrathin liquid metal micromesh electrodes fabricated through interfacial self-assembly of microparticles and subsequent laser sintering.These ultrathin electrodes(minimum thickness:317 nm)exhibit excellent stretchability(up to 1200%)and foldability,maintaining stable performance after 10,000 folding cycles at a 70μm bending radius.Their mechanical robustness arises from the unique micromesh architecture that disperses strain and alleviates stress concentration.It also confines the liquid metal within defined pathways,thereby preventing leakage(leakage resistance:968.75 kPa)and ensuring structural integrity under extreme deformation.Moreover,the micromesh structure endows the electrodes with excellent electrical stability(R/R_(o)=1.66 at 300%strain)and translucency.We demonstrate applications of these electrodes in flexible LED arrays,wireless power transfer,and angular sensing.展开更多
The increasing power density in applications such as aerospace,nuclear power,laser weapons,and phased array radar has led to a growing demand for efficient thermal management technologies.Spray cooling,known for its h...The increasing power density in applications such as aerospace,nuclear power,laser weapons,and phased array radar has led to a growing demand for efficient thermal management technologies.Spray cooling,known for its high heat flux dissipation and excellent temperature uniformity,has garnered great interest.Micro/nano-structured surfaces have been adopted to enhance spray cooling,especially in the phase-change heat transfer regime.However,manipulating bubble dynamics for non-interfering liquid and vapor flow paths remains a challenge under high heat flux conditions.This work employs a costeffective laser drilling technique to fabricate patterned multilayer perforated copper micromesh surfaces to enhance spray cooling.By creating separated liquid-vapor flow paths,bubble escape resistance is reduced,and the formation of vapor blankets within the perforated micromesh stack is delayed.Increasing the diameter and decreasing the separation between the perforations can strengthen the liquid and vapor transport,while reducing the liquid film boiling area.An analysis of flow resistance along bubble escape paths,caused by the anisotropic permeability of the multilayer micromesh in different directions,is performed to optimize the design of perforated microporous structures.A critical heat flux(CHF)of 1213 W/cm^(2),with a heat transfer coefficient(HTC)of 352.6 kW/(m^(2)K),is achieved on the patterned perforated micromesh surface,which is an improvement of 115%and 142%,respectively,compared to the plain surface.展开更多
The development of strain sensors with high stretchability and stability is an inevitable requirement for achieving full-range and long-term use of wearable electronic devices.Herein,a resistive micromesh reinforced s...The development of strain sensors with high stretchability and stability is an inevitable requirement for achieving full-range and long-term use of wearable electronic devices.Herein,a resistive micromesh reinforced strain sensor(MRSS)with high stretchability and stability is prepared,consisting of a laser-scribed graphene(LSG)layer and two styrene-block-poly(ethylene-ran-butylene)-block-poly-styrene micromesh layers embedded in Ecoflex.The micromesh reinforced structure endows the MRSS with combined characteris-tics of a high stretchability(120%),excellent stability(with a repetition error of 0.8%after 11000 cycles),and outstanding sensitivity(gauge factor up to 2692 beyond 100%).Impressively,the MRSS can still be used continauously within the working range without damage,even if stretched to 300%.Furthermore,compared with different structure sensors,the mechanism of the MRSS with high stretchability and stability is elucidated.What's more,a multilayer finite element model,based on the layered structure of the LSG and the morphology of the cracks,is proposed to investigate the strain sensing behavior and failure mechanism of the MRSS.Finally,due to the outstanding performance,the MRSS not only performes well in monitoring full-range human motions,but also achieves intelligent recognitions of various respiratory activities and ges-tures assisted by neural network algorithms(the accuracy up to 94.29%and 100%,respectively).This work provides a new approach for designing high-performance resistive strain sensors and shows great potential in full-range and long-term intelligent health management and human-machine interac-tions applications.展开更多
基金supported in part by the National Key R&D Program of China(No.2022YFF0705002)Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSCCIP001)+2 种基金Joint Research Fund for Overseas Chinese,Hong Kong and Macao Young Scholars(No.51929501)the Students’Innovation and Entrepreneurship Foundation of USTC(CY2024S014A)from the Institute of Innovation and Entrepreneurship,University of Science and Technology of Chinacarried out at the Instruments Center for Physical Science,University of Science and Technology of China.
文摘Gallium-based liquid metals are promising for stretchable electronics and beyond.However,their inherent fluidity and weak structural confinement in conventional films often cause leakage and functional failure under extreme deformation.Here,we report ultrathin liquid metal micromesh electrodes fabricated through interfacial self-assembly of microparticles and subsequent laser sintering.These ultrathin electrodes(minimum thickness:317 nm)exhibit excellent stretchability(up to 1200%)and foldability,maintaining stable performance after 10,000 folding cycles at a 70μm bending radius.Their mechanical robustness arises from the unique micromesh architecture that disperses strain and alleviates stress concentration.It also confines the liquid metal within defined pathways,thereby preventing leakage(leakage resistance:968.75 kPa)and ensuring structural integrity under extreme deformation.Moreover,the micromesh structure endows the electrodes with excellent electrical stability(R/R_(o)=1.66 at 300%strain)and translucency.We demonstrate applications of these electrodes in flexible LED arrays,wireless power transfer,and angular sensing.
基金supported by the National Natural Science Foundation of China(Grant No.52036002)。
文摘The increasing power density in applications such as aerospace,nuclear power,laser weapons,and phased array radar has led to a growing demand for efficient thermal management technologies.Spray cooling,known for its high heat flux dissipation and excellent temperature uniformity,has garnered great interest.Micro/nano-structured surfaces have been adopted to enhance spray cooling,especially in the phase-change heat transfer regime.However,manipulating bubble dynamics for non-interfering liquid and vapor flow paths remains a challenge under high heat flux conditions.This work employs a costeffective laser drilling technique to fabricate patterned multilayer perforated copper micromesh surfaces to enhance spray cooling.By creating separated liquid-vapor flow paths,bubble escape resistance is reduced,and the formation of vapor blankets within the perforated micromesh stack is delayed.Increasing the diameter and decreasing the separation between the perforations can strengthen the liquid and vapor transport,while reducing the liquid film boiling area.An analysis of flow resistance along bubble escape paths,caused by the anisotropic permeability of the multilayer micromesh in different directions,is performed to optimize the design of perforated microporous structures.A critical heat flux(CHF)of 1213 W/cm^(2),with a heat transfer coefficient(HTC)of 352.6 kW/(m^(2)K),is achieved on the patterned perforated micromesh surface,which is an improvement of 115%and 142%,respectively,compared to the plain surface.
基金supported by National Natural Science Foundation of China(Nos.62201624,32000939,21775168,22174167,51861145202,U20A20168)Shenzhen Science and Technology Program(No.RCBS20221008093310024)+2 种基金Shenzhen Research Funding Program(No.JCYJ20190807160401657,JCYJ201908073000608)the Open Research Fund Program of Beijing National Research Center for Information Science and Technology(No.BR2023KF02010)support from Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province(No.2020B1212060077).
文摘The development of strain sensors with high stretchability and stability is an inevitable requirement for achieving full-range and long-term use of wearable electronic devices.Herein,a resistive micromesh reinforced strain sensor(MRSS)with high stretchability and stability is prepared,consisting of a laser-scribed graphene(LSG)layer and two styrene-block-poly(ethylene-ran-butylene)-block-poly-styrene micromesh layers embedded in Ecoflex.The micromesh reinforced structure endows the MRSS with combined characteris-tics of a high stretchability(120%),excellent stability(with a repetition error of 0.8%after 11000 cycles),and outstanding sensitivity(gauge factor up to 2692 beyond 100%).Impressively,the MRSS can still be used continauously within the working range without damage,even if stretched to 300%.Furthermore,compared with different structure sensors,the mechanism of the MRSS with high stretchability and stability is elucidated.What's more,a multilayer finite element model,based on the layered structure of the LSG and the morphology of the cracks,is proposed to investigate the strain sensing behavior and failure mechanism of the MRSS.Finally,due to the outstanding performance,the MRSS not only performes well in monitoring full-range human motions,but also achieves intelligent recognitions of various respiratory activities and ges-tures assisted by neural network algorithms(the accuracy up to 94.29%and 100%,respectively).This work provides a new approach for designing high-performance resistive strain sensors and shows great potential in full-range and long-term intelligent health management and human-machine interac-tions applications.
基金Supported by the National Natural Science Foundation of China ( Grant No.50635040 , No .50805077)China Postdoctoral Science Foundation (Grant No .20070421008 ,No .200801373)Jiangsu Province Postdoctoral Science Foundation (Grant No.0702022B)
