Three-dimensional(3D)porous piezoresistive sensors are widely used because of their simple fabrication and convenient signal acquisition.However,because of the dependence on organic skeleton materials and the complexi...Three-dimensional(3D)porous piezoresistive sensors are widely used because of their simple fabrication and convenient signal acquisition.However,because of the dependence on organic skeleton materials and the complexity of conductive coating preparation,the electrical and mechanical properties of 3D wearable piezoresistive sensors have gradually failed to accommodate many emerging fields.Here,a new flexible 3D piezoresistive sensor(NF3PS)with high sensitivity and a wide measurement range is proposed,which comprises a natural porous loofah as a flexible framework and carbon fiber/carbon nanotube(CF/CNT)multiscale composite as a conductive coating.Composed of cellulose and lignin,the irregular,porous loofah has excellent mechanical strength,elasticity,and toughness,ensuring a repeated compression/recovery behavior of the NF3PS.In addition,compared with the single-size carbon coating,the coupling of multiscale CF/CNT composite coating improves sensitivities over a range of pressures.The NF3PS demonstrates a sensitivity of 6.94 kPa^(-1) with good linearity in the pressure range of 0–11.2 kPa and maintains a sensitivity of 0.28 kPa^(-1) in an ultrawide measurement range of 11.2–84.6 kPa.Considering flexibility,robustness,and wide-ranging linear resistance variation,the feasibility of the NF3PS in human activity monitoring,mechanical control,and smart homes is verified.This work provides a novel strategy for a new generation of 3D flexible pressure sensors for improving sensitivity and measurement range and demonstrates attractive applications in wearable sensors.展开更多
Based on the good extensibility and conductivity,the flexible sensors(FSs)have a wide range of applications in the field of the electrochemical energy storage and variable stress sensors,which causes that the preparat...Based on the good extensibility and conductivity,the flexible sensors(FSs)have a wide range of applications in the field of the electrochemical energy storage and variable stress sensors,which causes that the preparation of FSs also become a hot spot of research.Among the materials for preparing the FSs,the flexible carbon matrix composites(FCMCs)have become the widely used material since the good performance in the properties of electrochemistry and mechanics,which could be divided into three types:the carbon nanofibers(CNFs),the carbon nanospheres(CNSs)and the carbon nanotubes(CNTs).Compared with CNFs and CNSs,the CNTs wrapped by the polydimethylsiloxane(PDMS)have the advantages of the excellent extensibility and electrochemical stability.Therefore,the CNTs flexible sensor(CFS)could be well used in the field of the FSs.The purpose of this review is summarizing the preparation methods and application fields of CFS and proposing the research direction of CFS in the future.In this paper,two methods for fabricating the CFS have been designed by consulting the methods mentioned in the literature in recent years,and the advantages and disadvantages between the two methods have been explained.The application fields of CFS in recent years are enumerated,and the conclusion that the application fields of CFS are very wide is drawn.At the end of this paper,the review concludes with an overview of key remaining challenges in the application fields of the CFS.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52175554)the Natural Science Foundation of Hebei Province(Grant No.F2021409007)+2 种基金the Hebei Province Foundation for the Returned Overseas Chinese Scholars(Grant No.C20220103)the School Research Fund Project(Grant Nos.ZDYY-2021-01,YKY-2022-33)。
文摘Three-dimensional(3D)porous piezoresistive sensors are widely used because of their simple fabrication and convenient signal acquisition.However,because of the dependence on organic skeleton materials and the complexity of conductive coating preparation,the electrical and mechanical properties of 3D wearable piezoresistive sensors have gradually failed to accommodate many emerging fields.Here,a new flexible 3D piezoresistive sensor(NF3PS)with high sensitivity and a wide measurement range is proposed,which comprises a natural porous loofah as a flexible framework and carbon fiber/carbon nanotube(CF/CNT)multiscale composite as a conductive coating.Composed of cellulose and lignin,the irregular,porous loofah has excellent mechanical strength,elasticity,and toughness,ensuring a repeated compression/recovery behavior of the NF3PS.In addition,compared with the single-size carbon coating,the coupling of multiscale CF/CNT composite coating improves sensitivities over a range of pressures.The NF3PS demonstrates a sensitivity of 6.94 kPa^(-1) with good linearity in the pressure range of 0–11.2 kPa and maintains a sensitivity of 0.28 kPa^(-1) in an ultrawide measurement range of 11.2–84.6 kPa.Considering flexibility,robustness,and wide-ranging linear resistance variation,the feasibility of the NF3PS in human activity monitoring,mechanical control,and smart homes is verified.This work provides a novel strategy for a new generation of 3D flexible pressure sensors for improving sensitivity and measurement range and demonstrates attractive applications in wearable sensors.
基金supported by the Qingdao Postdoctoral Fund and Key Research (No. 2015118)the Development Plan of Shandong Province (No. 2017GGX50114 and No. 2018GGX105007)+1 种基金the Scientific Research Development Plan of Shandong Higher Education Institutions (No. J18KA316)National Natural Science Foundation of China (No. 60123456)
文摘Based on the good extensibility and conductivity,the flexible sensors(FSs)have a wide range of applications in the field of the electrochemical energy storage and variable stress sensors,which causes that the preparation of FSs also become a hot spot of research.Among the materials for preparing the FSs,the flexible carbon matrix composites(FCMCs)have become the widely used material since the good performance in the properties of electrochemistry and mechanics,which could be divided into three types:the carbon nanofibers(CNFs),the carbon nanospheres(CNSs)and the carbon nanotubes(CNTs).Compared with CNFs and CNSs,the CNTs wrapped by the polydimethylsiloxane(PDMS)have the advantages of the excellent extensibility and electrochemical stability.Therefore,the CNTs flexible sensor(CFS)could be well used in the field of the FSs.The purpose of this review is summarizing the preparation methods and application fields of CFS and proposing the research direction of CFS in the future.In this paper,two methods for fabricating the CFS have been designed by consulting the methods mentioned in the literature in recent years,and the advantages and disadvantages between the two methods have been explained.The application fields of CFS in recent years are enumerated,and the conclusion that the application fields of CFS are very wide is drawn.At the end of this paper,the review concludes with an overview of key remaining challenges in the application fields of the CFS.
