ZnO films on R-sapphire substrates are prepared and characterized by x-ray diffraction and scanning electron microscopy, which indicate that the thin films are well crystallized with (1120) texture. Love wave and Ra...ZnO films on R-sapphire substrates are prepared and characterized by x-ray diffraction and scanning electron microscopy, which indicate that the thin films are well crystallized with (1120) texture. Love wave and Rayleigh wave are used for fabrications of humidity sensors, which are excited in [1100] and [0001] directions of the (1120) ZnO piezoelectric films, respectively. The experimental results show that both kinds of sensors have good humidity response and repeatability, and the performances of the Love wave sensors are better than those of the Rayleigh wave sensors at room temperature. Moreover, the theoretical calculations of the mass sensitivity of the sensors are a/so carried out and the calculated results are in good agreement with the experimental measurements.展开更多
La-doped and undoped xBiIn03-(1 - x)PbTi03 (BI-PT) thin films are deposited on (101)SrRuO3/(lOO)Pt/(lO0) MgO substrates by the rf-magnetron sputtering method. The structures of the films are characterized by...La-doped and undoped xBiIn03-(1 - x)PbTi03 (BI-PT) thin films are deposited on (101)SrRuO3/(lOO)Pt/(lO0) MgO substrates by the rf-magnetron sputtering method. The structures of the films are characterized by XRD and SEM, and the results indicate that the thin films are grown with mainly (100) oriented and columnar structures. The ferroelectricity and piezoelectricity of the BI-PT films are also measured, and the measured results illustrate that both performances are effectively improved by the La-doping with suitable concentrations. These results will open up wide potential applications of the films in electronic devices.展开更多
Lead zirconate titanium solid-solution (PZT) thin films with variousthickness are synthesized on titanium substrates by repeated hydrothermal treatments. Young modulus,electric-field-induced displacement and the densi...Lead zirconate titanium solid-solution (PZT) thin films with variousthickness are synthesized on titanium substrates by repeated hydrothermal treatments. Young modulus,electric-field-induced displacement and the density of the PZT film are measured respectively.Bimorph- type bending actuators are fabricated using these films. The model, which is used toanalyze the driving ability of bimorph-type bending actuators by hydrothermal method, is set up. Itcan be seen that the driving ability of bimorph-type bending actuators can be greatly improved byoptimizing the thickness of PZT thin film and substrate from the theoretical analysis results. Themeasured values are expected to agree with the theoretical values calculated by the above model.展开更多
With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin fil...With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin film on elastic substrates. In this work, the bending of a bilayer comprising a piezoelectric film deposited on an elastic substrate, due to the mismatch, is investigated. An analytic formula relating the curvature of the bilayer to the mismatch, the electroelastic constants and the film thickness is obtained, and from this formula, a transverse piezoelectric constant d31 can be estimated. Meanwhile the influence of electrornechanical coupling coefficient on the curvature is discussed.展开更多
In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate (LZT) film are studied by X-ray diffraction (XRD) and scanning eletron microscope (SEM). The ratio of PbTi...In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate (LZT) film are studied by X-ray diffraction (XRD) and scanning eletron microscope (SEM). The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary (MPB). LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.展开更多
Piezoelectric materials play an increasingly important role in energy harvesters,sensors,and actuators.Flexible and thin piezoelectric films have been demonstrated to provide advanced functionalities and improved perf...Piezoelectric materials play an increasingly important role in energy harvesters,sensors,and actuators.Flexible and thin piezoelectric films have been demonstrated to provide advanced functionalities and improved performances.However,the research on flexible inorganic piezoelectric thin films has rarely been systematically summarized.Here,we summarize the recent advances in the flexible inorganic piezoelectric thin films,focusing on their structural designs,fabrication techniques,and applications in various practical scenarios.Specifically,different fabrication techniques suitable for diverse inorganic piezoelectric nanostructures are reviewed,including sol-gel,hydrothermal,electrospinning,and other techniques,and the integration process with flexible substrates is further discussed.Biomedical and industrial applications of the flexible piezoelectric thin films are emphasized.Finally,some existing challenges and future perspectives are discussed.展开更多
Apnoea,a major sleep disorder,affects many adults and causes several issues,such as fatigue,high blood pressure,liver conditions,increased risk of type II diabetes,and heart problems.Therefore,advanced monitoring and ...Apnoea,a major sleep disorder,affects many adults and causes several issues,such as fatigue,high blood pressure,liver conditions,increased risk of type II diabetes,and heart problems.Therefore,advanced monitoring and diagnosing tools of apnoea disorders are needed to facilitate better treatment,with advantages such as accuracy,comfort of use,cost effectiveness,and embedded computation capabilities to recognise,store,process,and transmit time series data.In this work we present an adaptation of our apnoea-Pi open-source surface acoustic wave(SAW)platform(Apnoea-Pi)to monitor and recognise apnoea in patients.The platform is based on a thin-film SAW device using bimorph ZnO and Al structures,including those fabricated as Al foils or plates,to achieve breath tracking based on humidity and temperature changes.We applied open-source electronics and provided embedded computing characteristics for signal processing,data recognition,storage,and transmission of breath signals.We show that the thin-film SAW device out-performed standard and off-the-shelf capacitive electronic sensors in terms of their response and accuracy for human breath-tracking purposes.This in combination with embedded electronics makes a suitable platform for human breath monitoring and sleep disorder recognition.展开更多
A piezoelectric micro active suspension device has been developed for the application of active isolation of sensitive electronic devices such as frequency generators or inertial sensors.The developed strategy is base...A piezoelectric micro active suspension device has been developed for the application of active isolation of sensitive electronic devices such as frequency generators or inertial sensors.The developed strategy is based on a classical skyhook active damper but adapted and optimised to allow robust implementation onto an adaptive microelectromechanical systems(MEMS).The micro suspension is a silicon beam structure etched in a silicon on insulator(SOI)wafer and is equipped with a pair of piezoelectric transducers obtained from a lead zirconate titanante thin film sandwiched between pairs of electrodes.High performance transducers allow application of the active isolation strategy and demonstrate the possibility to implement skyhook damping with low-voltage control level.展开更多
Aiming at the problems of loose bowl,nutritive bowl damage and planting leakage caused by lack of perception and detection of seedling clamping force in vegetable transplanting,a semi-micro-column structure sensor for...Aiming at the problems of loose bowl,nutritive bowl damage and planting leakage caused by lack of perception and detection of seedling clamping force in vegetable transplanting,a semi-micro-column structure sensor for measuring potted seedling clamping force was developed based on polyvinylidene fluoride(PVDF)piezoelectric film.The diameter of the semi-micro-column is 4 mm.The size of the force probe is 14 mm×30 mm,the encapsulation position of the force probe is 25 mm away from the tip of the seedling claw.The hardware circuit for sensor signal acquisition including pre-amplification module,power frequency notch module,low-pass filter module,processor module and power module was designed.The circuit completes charge-voltage conversion,clamping force signal amplification,power frequency signal elimination,vibration and noise elimination,and ensures the accurate acquisition of clamping force signal.In order to verify the sensor performance,sensor calibration tests and indoor experiments were carried out respectively.The calibration tests showed that the sensitivity of the clamping force sensor was 0.5264 V/N,the linearity was 4.74%,the accuracy was 6.51%,the hysteresis was 3.63%,and the range was 8 N under the impact of different waveforms and frequencies,which fully meet the accuracy requirements of the clamping force detection during transplanting.Indoor experiments showed that the clamping force sensor had good stability and adaptability under different seedling frequencies.The sensor can provide useful reference for the perception and detection of seedling clamping force and the feedback regulation of seedling clamping force.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174142,11304160 and 11404147the National Basic Research Program of China under Grant No 2012CB921504+2 种基金the PAPD Projectthe Natural Science Foundation of Jiangsu Higher Education Institutions of China under Grant No 13KJB140008the Foundation of Nanjing University of Posts and Telecommunications under Grant No NY213018
文摘ZnO films on R-sapphire substrates are prepared and characterized by x-ray diffraction and scanning electron microscopy, which indicate that the thin films are well crystallized with (1120) texture. Love wave and Rayleigh wave are used for fabrications of humidity sensors, which are excited in [1100] and [0001] directions of the (1120) ZnO piezoelectric films, respectively. The experimental results show that both kinds of sensors have good humidity response and repeatability, and the performances of the Love wave sensors are better than those of the Rayleigh wave sensors at room temperature. Moreover, the theoretical calculations of the mass sensitivity of the sensors are a/so carried out and the calculated results are in good agreement with the experimental measurements.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174142 and 11304160he National Basic Research Program of China under Grant No 2012CB921504the Special Fund for Public Interest of China under Grant No201510068
文摘La-doped and undoped xBiIn03-(1 - x)PbTi03 (BI-PT) thin films are deposited on (101)SrRuO3/(lOO)Pt/(lO0) MgO substrates by the rf-magnetron sputtering method. The structures of the films are characterized by XRD and SEM, and the results indicate that the thin films are grown with mainly (100) oriented and columnar structures. The ferroelectricity and piezoelectricity of the BI-PT films are also measured, and the measured results illustrate that both performances are effectively improved by the La-doping with suitable concentrations. These results will open up wide potential applications of the films in electronic devices.
基金This project is supported by National Natural Science Foundation of China(No.90207003) and Returnee Foundation of Dalian.
文摘Lead zirconate titanium solid-solution (PZT) thin films with variousthickness are synthesized on titanium substrates by repeated hydrothermal treatments. Young modulus,electric-field-induced displacement and the density of the PZT film are measured respectively.Bimorph- type bending actuators are fabricated using these films. The model, which is used toanalyze the driving ability of bimorph-type bending actuators by hydrothermal method, is set up. Itcan be seen that the driving ability of bimorph-type bending actuators can be greatly improved byoptimizing the thickness of PZT thin film and substrate from the theoretical analysis results. Themeasured values are expected to agree with the theoretical values calculated by the above model.
基金Project supported by the Zhejiang Provincial Natural Science Foundation,China(Grant No.Y6100440)
文摘With the trends in miniaturization, and particularly the introduction of micro- and nano-electro-mechanical system, piezoelectric materials used in microelectronic devices are deposited usually in the form of thin film on elastic substrates. In this work, the bending of a bilayer comprising a piezoelectric film deposited on an elastic substrate, due to the mismatch, is investigated. An analytic formula relating the curvature of the bilayer to the mismatch, the electroelastic constants and the film thickness is obtained, and from this formula, a transverse piezoelectric constant d31 can be estimated. Meanwhile the influence of electrornechanical coupling coefficient on the curvature is discussed.
基金This project is supported by National Natural Science Foundation of China (No.50675025)Scientific Research Foundation of Ministry of Education,Dalian City for the Returned Overseas Chinese ScholarsDoctoral Startup Fund of Liaoning Province of China (No.20051080).
文摘In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate (LZT) film are studied by X-ray diffraction (XRD) and scanning eletron microscope (SEM). The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary (MPB). LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.
基金supported by the National Natural Science Foundation of China(No.12072189)Medicine and Engineering Interdisciplinary Research Fund of Shanghai Jiao Tong University(No.YG2021QN132)+1 种基金Science Foundation of National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(No.6142905223704)The authors are also grateful to Center for Advanced Electronic Materials and Devices(AEMD)of Shanghai Jiao Tong University.
文摘Piezoelectric materials play an increasingly important role in energy harvesters,sensors,and actuators.Flexible and thin piezoelectric films have been demonstrated to provide advanced functionalities and improved performances.However,the research on flexible inorganic piezoelectric thin films has rarely been systematically summarized.Here,we summarize the recent advances in the flexible inorganic piezoelectric thin films,focusing on their structural designs,fabrication techniques,and applications in various practical scenarios.Specifically,different fabrication techniques suitable for diverse inorganic piezoelectric nanostructures are reviewed,including sol-gel,hydrothermal,electrospinning,and other techniques,and the integration process with flexible substrates is further discussed.Biomedical and industrial applications of the flexible piezoelectric thin films are emphasized.Finally,some existing challenges and future perspectives are discussed.
基金financially supported by the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/P018998/1the UK Fluidic Network Special Interest Group of Acoustofluidics (EP/N032861/1).
文摘Apnoea,a major sleep disorder,affects many adults and causes several issues,such as fatigue,high blood pressure,liver conditions,increased risk of type II diabetes,and heart problems.Therefore,advanced monitoring and diagnosing tools of apnoea disorders are needed to facilitate better treatment,with advantages such as accuracy,comfort of use,cost effectiveness,and embedded computation capabilities to recognise,store,process,and transmit time series data.In this work we present an adaptation of our apnoea-Pi open-source surface acoustic wave(SAW)platform(Apnoea-Pi)to monitor and recognise apnoea in patients.The platform is based on a thin-film SAW device using bimorph ZnO and Al structures,including those fabricated as Al foils or plates,to achieve breath tracking based on humidity and temperature changes.We applied open-source electronics and provided embedded computing characteristics for signal processing,data recognition,storage,and transmission of breath signals.We show that the thin-film SAW device out-performed standard and off-the-shelf capacitive electronic sensors in terms of their response and accuracy for human breath-tracking purposes.This in combination with embedded electronics makes a suitable platform for human breath monitoring and sleep disorder recognition.
文摘A piezoelectric micro active suspension device has been developed for the application of active isolation of sensitive electronic devices such as frequency generators or inertial sensors.The developed strategy is based on a classical skyhook active damper but adapted and optimised to allow robust implementation onto an adaptive microelectromechanical systems(MEMS).The micro suspension is a silicon beam structure etched in a silicon on insulator(SOI)wafer and is equipped with a pair of piezoelectric transducers obtained from a lead zirconate titanante thin film sandwiched between pairs of electrodes.High performance transducers allow application of the active isolation strategy and demonstrate the possibility to implement skyhook damping with low-voltage control level.
基金sponsored by the National Key Research and Development Program of China Project(No.2016YFD0700100)the National Natural Science Foundation of China(No.51875175)+2 种基金the Key Research and Development Program of Guangdong Province(No.2019B020222004)the Innovation Scientists and Technicians Talent Projects of Henan Provincial Department of Education(No.19HASTIT021)the Innovation Scientists and Technicians Troop Construction Projects of Henan Province(No.184200510017).
文摘Aiming at the problems of loose bowl,nutritive bowl damage and planting leakage caused by lack of perception and detection of seedling clamping force in vegetable transplanting,a semi-micro-column structure sensor for measuring potted seedling clamping force was developed based on polyvinylidene fluoride(PVDF)piezoelectric film.The diameter of the semi-micro-column is 4 mm.The size of the force probe is 14 mm×30 mm,the encapsulation position of the force probe is 25 mm away from the tip of the seedling claw.The hardware circuit for sensor signal acquisition including pre-amplification module,power frequency notch module,low-pass filter module,processor module and power module was designed.The circuit completes charge-voltage conversion,clamping force signal amplification,power frequency signal elimination,vibration and noise elimination,and ensures the accurate acquisition of clamping force signal.In order to verify the sensor performance,sensor calibration tests and indoor experiments were carried out respectively.The calibration tests showed that the sensitivity of the clamping force sensor was 0.5264 V/N,the linearity was 4.74%,the accuracy was 6.51%,the hysteresis was 3.63%,and the range was 8 N under the impact of different waveforms and frequencies,which fully meet the accuracy requirements of the clamping force detection during transplanting.Indoor experiments showed that the clamping force sensor had good stability and adaptability under different seedling frequencies.The sensor can provide useful reference for the perception and detection of seedling clamping force and the feedback regulation of seedling clamping force.