Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating m...Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating mechanisms to achieve bimodal detection,leading to complex device architectures and challenges in signal decoupling.In this work,we address these limitations by leveraging the unique piezotronic effect of Y-ion-doped ZnO to develop a bimodal piezotronic sensor(BPS)with a simplified structure and enhanced sensitivity.Through a combination of finite element simulations and experimental validation,we demonstrate that the BPS can effectively monitor both dynamic and static forces,achieving an on/off ratio of 1029,a gauge factor of 23,439 and a static force response duration of up to 600 s,significantly outperforming the performance of conventional piezoelectric sensors.As a proof-of-concept,the BPS demonstrates the continuous monitoring of Achilles tendon behavior under mixed dynamic and static loading conditions.Aided by deep learning algorithms,the system achieves 96%accuracy in identifying Achilles tendon movement patterns,thus enabling warnings for dangerous movements.This work provides a viable strategy for bimodal force monitoring,highlighting its potential in wearable electronics.展开更多
Bioinspired soft robots hold great potential to perform tasks in unstructured terrains.Ferroelectric polymers are highly valued in soft robots for their flexibility,lightweight,and electrically controllable deformatio...Bioinspired soft robots hold great potential to perform tasks in unstructured terrains.Ferroelectric polymers are highly valued in soft robots for their flexibility,lightweight,and electrically controllable deformation.However,achieving large strains in ferroelectric polymers typically requires high driving voltages,posing a significant challenge for practical applications.In this study,we investigate the role of crystalline domain size in enhancing the electrostrain performance of the relaxor ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene-fluorinated alkynes)(P(VDFTrFE-CFE-FA)).Leveraging its remarkable inverse piezoelectric coefficient(|d33^(*)|=701 pm V^(-1)),we demonstrate that the planar films exhibit a five times larger bending angle than that of commercial PVDF films at low electric fields.Based on this material,we design a petal-structured soft robot that achieves a curvature of up to 4.5 cm^(-1) at a DC electric field of 30 Vμm^(-1).When integrated into a bipedal soft robot,it manifests outstanding electrostrain performance,achieving rapid locomotion of~19 body lengths per second(BL s^(-1))at 10 Vμm^(-1)(560 Hz).Moreover,the developed robot demonstrates remarkable abilities in climbing slopes and carrying heavy loads.These findings open new avenues for developing low-voltage-driven soft robots with significant promise for practical applications.展开更多
Piezoelectric nanofibers have received extensive attention in the field of electronic devices,but they are still restricted for further development,due to their limited dipole arrangement.Herein,we propose spatially c...Piezoelectric nanofibers have received extensive attention in the field of electronic devices,but they are still restricted for further development,due to their limited dipole arrangement.Herein,we propose spatially confined MXene/polyvinylidene fluoride(PVDF)nanofibers for piezoelectric application,with dual functions of pressure sensing and energy harvesting.The spatial confinement of MXene/PVDF nanofibers can actively induce the optimally aligned-CH_(2)-/-CF_(2)-dipoles of PVDF and dramatically boost spontaneous polarization for piezoelectric enhancement.The voltage and current generated by fabricated MXene/PVDF(0.8 wt%)nanofiber piezoelectric electronic devices are respectively 3.97 times and 10.1 times higher than those generated by pure PVDF nanofibers.Based on these results,the developed bifunctional electronic devices are applied to monitor various human movements and to harvest energy.Notably,the results of this work allow for the development of nanofibers with excellent piezoelectric performance using a spatial confinement mechanism.展开更多
Respiration is a critical physiological process of the body and plays an essential role in maintaining human health.Wearable piezoelectric nanofiber-based respiratory monitoring has attracted much attention due to its...Respiration is a critical physiological process of the body and plays an essential role in maintaining human health.Wearable piezoelectric nanofiber-based respiratory monitoring has attracted much attention due to its self-power,high linearity,noninvasiveness,and convenience.However,the limited sensitivity of conventional piezoelectric nanofibers makes it difficult to meet medical and daily respiratory monitoring requirements due to their low electromechanical conversion efficiency.Here,we present a universally applicable,highly sensitive piezoelectric nanofiber characterized by a coaxial composite structure of polyvinylidene fluoride(PVDF)and carbon nanotube(CNT),which is denoted as PS-CC.Based on elucidating the enhancement mechanism from the percolation effect,PS-CC exhibits excellent sensing performance with a high sensitivity of 3.7 V/N and a fast response time of 20 ms for electromechanical conversion.As a proof-of-concept,the nanofiber membrane is seamlessly integrated into a facial mask,facilitating accurate recognition of respiratory states.With the assistance of a one-dimensional convolutional neural network(CNN),a PS-CC-based smart mask can recognize respiratory tracts and multiple breathing patterns with a classification accuracy of up to 97.8%.Notably,this work provides an effective strategy for monitoring respiratory diseases and offers widespread utility for daily health monitoring and clinical applications.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U2330120)the Natural Science Foundation of Sichuan Province of China(No.2023NSFSC0313)the Basic Research Cultivation Project of Southwest Jiaotong University(No.2682023KJ024)。
文摘Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating mechanisms to achieve bimodal detection,leading to complex device architectures and challenges in signal decoupling.In this work,we address these limitations by leveraging the unique piezotronic effect of Y-ion-doped ZnO to develop a bimodal piezotronic sensor(BPS)with a simplified structure and enhanced sensitivity.Through a combination of finite element simulations and experimental validation,we demonstrate that the BPS can effectively monitor both dynamic and static forces,achieving an on/off ratio of 1029,a gauge factor of 23,439 and a static force response duration of up to 600 s,significantly outperforming the performance of conventional piezoelectric sensors.As a proof-of-concept,the BPS demonstrates the continuous monitoring of Achilles tendon behavior under mixed dynamic and static loading conditions.Aided by deep learning algorithms,the system achieves 96%accuracy in identifying Achilles tendon movement patterns,thus enabling warnings for dangerous movements.This work provides a viable strategy for bimodal force monitoring,highlighting its potential in wearable electronics.
基金National Natural Science Foundation of China,Grant/Award Number:U2330120Natural Science Foundation of Sichuan Province of China,Grant/Award Number:2023NSFSC0313Basic Research Cultivation Project of Southwest Jiaotong University,Grant/Award Number:2682023KJ024。
文摘Bioinspired soft robots hold great potential to perform tasks in unstructured terrains.Ferroelectric polymers are highly valued in soft robots for their flexibility,lightweight,and electrically controllable deformation.However,achieving large strains in ferroelectric polymers typically requires high driving voltages,posing a significant challenge for practical applications.In this study,we investigate the role of crystalline domain size in enhancing the electrostrain performance of the relaxor ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene-fluorinated alkynes)(P(VDFTrFE-CFE-FA)).Leveraging its remarkable inverse piezoelectric coefficient(|d33^(*)|=701 pm V^(-1)),we demonstrate that the planar films exhibit a five times larger bending angle than that of commercial PVDF films at low electric fields.Based on this material,we design a petal-structured soft robot that achieves a curvature of up to 4.5 cm^(-1) at a DC electric field of 30 Vμm^(-1).When integrated into a bipedal soft robot,it manifests outstanding electrostrain performance,achieving rapid locomotion of~19 body lengths per second(BL s^(-1))at 10 Vμm^(-1)(560 Hz).Moreover,the developed robot demonstrates remarkable abilities in climbing slopes and carrying heavy loads.These findings open new avenues for developing low-voltage-driven soft robots with significant promise for practical applications.
基金supported by the Postdoctoral Innovation Talents Support Program(No.BX20220257)the Multiple Clean Energy Harvesting System(No.YYF20223026)+2 种基金the Sichuan Science and Technology Program(No.2023NSFSC0313)a Catalyst Seeding General Grant administered by the Royal Society of New Zealand(Contract 20-UOA-035-CSG)The authors are grateful for the help from the Analysis and Testing Center of Southwest Jiaotong University.
文摘Piezoelectric nanofibers have received extensive attention in the field of electronic devices,but they are still restricted for further development,due to their limited dipole arrangement.Herein,we propose spatially confined MXene/polyvinylidene fluoride(PVDF)nanofibers for piezoelectric application,with dual functions of pressure sensing and energy harvesting.The spatial confinement of MXene/PVDF nanofibers can actively induce the optimally aligned-CH_(2)-/-CF_(2)-dipoles of PVDF and dramatically boost spontaneous polarization for piezoelectric enhancement.The voltage and current generated by fabricated MXene/PVDF(0.8 wt%)nanofiber piezoelectric electronic devices are respectively 3.97 times and 10.1 times higher than those generated by pure PVDF nanofibers.Based on these results,the developed bifunctional electronic devices are applied to monitor various human movements and to harvest energy.Notably,the results of this work allow for the development of nanofibers with excellent piezoelectric performance using a spatial confinement mechanism.
基金supported by the Sichuan Science and Technology Program(No.2023NSFSC0313)the Basic Research Cultivation Project of Southwest Jiaotong University(No.2682023KJ024).
文摘Respiration is a critical physiological process of the body and plays an essential role in maintaining human health.Wearable piezoelectric nanofiber-based respiratory monitoring has attracted much attention due to its self-power,high linearity,noninvasiveness,and convenience.However,the limited sensitivity of conventional piezoelectric nanofibers makes it difficult to meet medical and daily respiratory monitoring requirements due to their low electromechanical conversion efficiency.Here,we present a universally applicable,highly sensitive piezoelectric nanofiber characterized by a coaxial composite structure of polyvinylidene fluoride(PVDF)and carbon nanotube(CNT),which is denoted as PS-CC.Based on elucidating the enhancement mechanism from the percolation effect,PS-CC exhibits excellent sensing performance with a high sensitivity of 3.7 V/N and a fast response time of 20 ms for electromechanical conversion.As a proof-of-concept,the nanofiber membrane is seamlessly integrated into a facial mask,facilitating accurate recognition of respiratory states.With the assistance of a one-dimensional convolutional neural network(CNN),a PS-CC-based smart mask can recognize respiratory tracts and multiple breathing patterns with a classification accuracy of up to 97.8%.Notably,this work provides an effective strategy for monitoring respiratory diseases and offers widespread utility for daily health monitoring and clinical applications.
