Nature creatures have evolved excellent receptors, such as sensory hairs in arthropods, lateral line system of fishes. Researchers inspired by nature creatures have developed various mechanical sensors. Here, we provi...Nature creatures have evolved excellent receptors, such as sensory hairs in arthropods, lateral line system of fishes. Researchers inspired by nature creatures have developed various mechanical sensors. Here, we provide an overview on the development of Artificial Hair-Like （AHL） sensors based on the inspiration of hair flow sensory receptors, especially sensory hairs in arthropods and lateral line systems of fishes. We classify the developed AHL sensors into several categories according to the operating principles they based on, for example, piezoresistive and piezoelectric effects. The current challenges and existing problems in the development of AHL sensors are also present, which were primarily restricted by the exploratory tools of sensing mechanism of creatures and current manufacturing technologies. In future, more efforts are required in order to further improve the performance of AHL sensors. We expect that intelligent multi-functional AHL sensors can be applied not only in applications like navigation of underwater automatic vehicles, underwater search and rescue, tap-water metering, air monitoring and even in medicare, but also potentially be used in space robots to detect complex to- pography.展开更多
Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into...Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.展开更多
Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D f...Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D fliers reported previously,a class of 3 D electronic fliers inspired by wind-dispersed seeds show promising potentials,owing to the lightweight and noiseless features,aside from the stable rotational fall associated with a low falling velocity.While on-demand shape-morphing capabilities are essential for those 3 D electronic fliers,the realization of such miniaturized systems remains very challenging,due to the lack of fast-response 3 D actuators that can be seamlessly integrated with 3 D electronic fliers.Here we develop a type of morphable3 D mesofliers with shape memory polymer(SMP)-based electrothermal actuators,capable of large degree of actuation deformations,with a fast response(e.g.,~1 s).Integration of functional components,including sensors,controllers,and chip batteries,enables development of intelligent 3 D mesoflier systems that can achieve the on-demand unfolding,triggered by the processing of real-time sensed information(e.g.,acceleration and humidity data).Such intelligent electronic mesofliers are capable of both the low-air-drag rising and the low-velocity falling,and thereby,can be used to measure the humidity fields in a wide 3 D space by simple hand throwing,according to our demonstrations.The developed electronic mesofliers can also be integrated with other types of physical/chemical sensors for uses in different application scenarios.展开更多
Due to its real-time control,high folding ratio,and structure self-locking,flexible large curvature self-folding devices have broad application prospects,such as foldable human implants,flexible electronics,and flexib...Due to its real-time control,high folding ratio,and structure self-locking,flexible large curvature self-folding devices have broad application prospects,such as foldable human implants,flexible electronics,and flexible robots.Driven by this background,flexible large curvature folding butterfly(Polyura eudamippus)proboscises were studied in this work.The folding ratio of the proboscises was about 15.The curvature of coiled proboscises ranged from about 150 m_1 to 880 m The external and internal structures of the proboscises were studied by different methods.Three main strategies for large-curvature folding of proboscises were identified:a gradual decrease in thickness,a lower elastic modulus,and(most importantly)large numbers of regular corrugated cracks arranged on the surface.These corrugated cracks can effectively accommodate the coiled strain and provide space for the large curvature folding of proboscises.Finally,a 4D printed coiled sample with corrugated cracks was fabricated to mimic the proboscises stretching process.Large-curvature folding strategies,based on these proboscises,provide insights for the biomimetic design of artificial highly folded components.展开更多
The paper revealed the fine structure of the scorpion （Mesobuthus martensii） pectines and showed how the fine structure of the pecten influences odor flow. The first step of our investigation was to prove that scorp...The paper revealed the fine structure of the scorpion （Mesobuthus martensii） pectines and showed how the fine structure of the pecten influences odor flow. The first step of our investigation was to prove that scorpion pectines work as olfactory and this was done via experiments utilizing paraffin coverage. Subsequently, the location, morphology, section structure, and arrange- ment of the pectines were studied via stereomicroscopy and Scanning Electron Microscopy （SEM）. The fine structure of pecten comprises a comb-like structure with 24-30 knife-like teeth and thousands of micron bowl-like pecten sensilla in staggered arrangement on the surface of the tooth. Computational Fluid Dynamics （CFD） was applied to predict odor flow around the pecten via the relevant Reynolds numbers. The comb-like structure amplified the odor flow velocity similar to an amplifier, transporting the odor flow of increased velocity to the micron pecten sensilla, improving transport efficiency of the odor flow. The staggered arrangement of the pecten sensilla generated a vortex, improving contact duration between pecten sensilla and odorant molecules. Thus, the pecten fine structure was likely acting as an effective comb with non-smooth teeth for the transport and capture of odorant molecules.展开更多
Recently,micro-vibrational perception mechanisms of nocturnal arthropods such as scorpions and spiders are attracting increasingly more attention and research.The relevant micro-vibrational receptors are exquisite,in ...Recently,micro-vibrational perception mechanisms of nocturnal arthropods such as scorpions and spiders are attracting increasingly more attention and research.The relevant micro-vibrational receptors are exquisite,in terms of their comprehensive performance such as sensitivity,stability,high anti-interference,and ultralow-power consumption.In this work,we find the Basitarsal Compound Slit Sensilla (BCSS) of scorpion (Heterometrus petersii) are composed of the crack-shaped slits as mechanosensory structure and can efficiently detect substrate-borne vibrational signal in complex natural environment.The study on microstructures and mechanical properties of tissue phases constituting the BCSS reveals that the strategy of tessellation is used to make crack-shaped slit amplify the tiny mechanical signal.In addition,the magnitude-frequency characteristics of electrophysiological signals caused by vibration stimulation with different frequencies indicate that the scorpion is sensitive to micro-vibrational signals at a certain frequency range.Meanwhile,the vibrational perception mechanism based on geometrical amplification and resonance is proposed to explain how scorpions detect the tiny biotic vibrational signal efficiently in noise environment.This finding not only promotes our further understanding of ultra-sensitive mechanism of the vibrational receptors,but also provides biological inspiration for the next generation of mechanosensor for a broad range of applications.展开更多
Fault diagnosis is vital in manufacturing system.However,the first step of the traditional fault diagnosis method is to process the signal,extract the features and then put the features into a selected classifier for ...Fault diagnosis is vital in manufacturing system.However,the first step of the traditional fault diagnosis method is to process the signal,extract the features and then put the features into a selected classifier for classification.The process of feature extraction depends on the experimenters’experience,and the classification rate of the shallow diagnostic model does not achieve satisfactory results.In view of these problems,this paper proposes a method of converting raw signals into twodimensional images.This method can extract the features of the converted two-dimensional images and eliminate the impact of expert’s experience on the feature extraction process.And it follows by proposing an intelligent diagnosis algorithm based on Convolution Neural Network(CNN),which can automatically accomplish the process of the feature extraction and fault diagnosis.The effect of this method is verified by bearing data.The influence of different sample sizes and different load conditions on the diagnostic capability of this method is analyzed.The results show that the proposed method is effective and can meet the timeliness requirements of fault diagnosis.展开更多
It is quite often that the theoretic model used in the Kalman filtering may not be sufficiently accurate for practical applications,due to the fact that the covariances of noises are not exactly known.Our previous wor...It is quite often that the theoretic model used in the Kalman filtering may not be sufficiently accurate for practical applications,due to the fact that the covariances of noises are not exactly known.Our previous work reveals that in such scenario the filter calculated mean square errors(FMSE)and the true mean square errors(TMSE)become inconsistent,while FMSE and TMSE are consistent in the Kalman filter with accurate models.This can lead to low credibility of state estimation regardless of using Kalman filters or adaptive Kalman filters.Obviously,it is important to study the inconsistency issue since it is vital to understand the quantitative influence induced by the inaccurate models.Aiming at this,the concept of credibility is adopted to discuss the inconsistency problem in this paper.In order to formulate the degree of the credibility,a trust factor is constructed based on the FMSE and the TMSE.However,the trust factor can not be directly computed since the TMSE cannot be found for practical applications.Based on the definition of trust factor,the estimation of the trust factor is successfully modified to online estimation of the TMSE.More importantly,a necessary and sufficient condition is found,which turns out to be the basis for better design of Kalman filters with high performance.Accordingly,beyond trust factor estimation with Sage-Husa technique(TFE-SHT),three novel trust factor estimation methods,which are directly numerical solving method(TFE-DNS),the particle swarm optimization method(PSO)and expectation maximization-particle swarm optimization method(EM-PSO)are proposed.The analysis and simulation results both show that the proposed TFE-DNS is better than the TFE-SHT for the case of single unknown noise covariance.Meanwhile,the proposed EMPSO performs completely better than the EM and PSO on the estimation of the credibility degree and state when both noise covariances should be estimated online.展开更多
基金This research was supported by the Natural Science Foundation of China （Nos. 51325501, 51675220 and 51205161）, Natural Science Foundation of Jilin Province of China （No. 20170101115JC）, the 13th Five-Year scientific research project of Education Department of Jilin Province （No. 2015474）.
文摘Nature creatures have evolved excellent receptors, such as sensory hairs in arthropods, lateral line system of fishes. Researchers inspired by nature creatures have developed various mechanical sensors. Here, we provide an overview on the development of Artificial Hair-Like （AHL） sensors based on the inspiration of hair flow sensory receptors, especially sensory hairs in arthropods and lateral line systems of fishes. We classify the developed AHL sensors into several categories according to the operating principles they based on, for example, piezoresistive and piezoelectric effects. The current challenges and existing problems in the development of AHL sensors are also present, which were primarily restricted by the exploratory tools of sensing mechanism of creatures and current manufacturing technologies. In future, more efforts are required in order to further improve the performance of AHL sensors. We expect that intelligent multi-functional AHL sensors can be applied not only in applications like navigation of underwater automatic vehicles, underwater search and rescue, tap-water metering, air monitoring and even in medicare, but also potentially be used in space robots to detect complex to- pography.
基金This work was supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.52021003)National Natural Science Foundation of China(Grant No.51835006)+6 种基金the National Natural Science Foundation of China(Grant Nos.52222509,52105301,U19A20103)Jilin University Science and Technology Innovative Research Team(Grant No.2020TD-03)Interdisciplinary Integration and Innovation Project of JLU(Grant No.JLUXKJC2021ZZ03)the Natural Science Foundation of Jilin Province(Grant No.20220101220JC)Education Department of Jilin Province(Grant No.JJKH20220979KJ)Graduate Innovation Fund of Jilin University(2023CX077)supported by“Fundamental Research Funds for the Central Universities.”。
文摘Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.
基金support from the National Natural Science Foundation of China(12050004 and 11921002)the Tsinghua National Laboratory for Information Science and Technology,and a grant from the Institute for Guo Qiang,Tsinghua University(2019GQG1012)+3 种基金support from the National Natural Science Foundation of China(11902178)the Natural Science Foundation of Beijing Municipality(3204043)China Postdoctoral Science Foundation(2019M650648)support from the National Natural Science Foundation of China(61904095)。
文摘Development of miniaturized three-dimensional(3 D)fliers with integrated functional components has important implications to a diverse range of engineering areas.Among the various active and passive miniaturized 3 D fliers reported previously,a class of 3 D electronic fliers inspired by wind-dispersed seeds show promising potentials,owing to the lightweight and noiseless features,aside from the stable rotational fall associated with a low falling velocity.While on-demand shape-morphing capabilities are essential for those 3 D electronic fliers,the realization of such miniaturized systems remains very challenging,due to the lack of fast-response 3 D actuators that can be seamlessly integrated with 3 D electronic fliers.Here we develop a type of morphable3 D mesofliers with shape memory polymer(SMP)-based electrothermal actuators,capable of large degree of actuation deformations,with a fast response(e.g.,~1 s).Integration of functional components,including sensors,controllers,and chip batteries,enables development of intelligent 3 D mesoflier systems that can achieve the on-demand unfolding,triggered by the processing of real-time sensed information(e.g.,acceleration and humidity data).Such intelligent electronic mesofliers are capable of both the low-air-drag rising and the low-velocity falling,and thereby,can be used to measure the humidity fields in a wide 3 D space by simple hand throwing,according to our demonstrations.The developed electronic mesofliers can also be integrated with other types of physical/chemical sensors for uses in different application scenarios.
基金This work was funded by the project of National Key R&D Program of China(No.2018YFA0703300)the Program for HUST Academic Frontier Youth Team of“4D Printing Technology”(No.2018QYTD04)+5 种基金Science and Technology Project of Wuhan(No.2018010401011281)Natural Science Foundation of Hubei Province(No.2018CFB502)State Key Labora-tory of Materials Processing and Die&Mould Tech-nology,Huazhong University of Science and Technol-ogy(No.P2019-006)China Postdoctoral Science Foundation(No.2019M650648)Beiing Natural Science Foundation(No.3204043)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(No.K201901,No.K201903).
文摘Due to its real-time control,high folding ratio,and structure self-locking,flexible large curvature self-folding devices have broad application prospects,such as foldable human implants,flexible electronics,and flexible robots.Driven by this background,flexible large curvature folding butterfly(Polyura eudamippus)proboscises were studied in this work.The folding ratio of the proboscises was about 15.The curvature of coiled proboscises ranged from about 150 m_1 to 880 m The external and internal structures of the proboscises were studied by different methods.Three main strategies for large-curvature folding of proboscises were identified:a gradual decrease in thickness,a lower elastic modulus,and(most importantly)large numbers of regular corrugated cracks arranged on the surface.These corrugated cracks can effectively accommodate the coiled strain and provide space for the large curvature folding of proboscises.Finally,a 4D printed coiled sample with corrugated cracks was fabricated to mimic the proboscises stretching process.Large-curvature folding strategies,based on these proboscises,provide insights for the biomimetic design of artificial highly folded components.
基金This study was funded by the Nature Science Foundation of China （Nos. 51675220 51325501 51205161）, Natural Science Foundation of Jilin Prov- ince of China （No. 20170101115JC）.
文摘The paper revealed the fine structure of the scorpion （Mesobuthus martensii） pectines and showed how the fine structure of the pecten influences odor flow. The first step of our investigation was to prove that scorpion pectines work as olfactory and this was done via experiments utilizing paraffin coverage. Subsequently, the location, morphology, section structure, and arrange- ment of the pectines were studied via stereomicroscopy and Scanning Electron Microscopy （SEM）. The fine structure of pecten comprises a comb-like structure with 24-30 knife-like teeth and thousands of micron bowl-like pecten sensilla in staggered arrangement on the surface of the tooth. Computational Fluid Dynamics （CFD） was applied to predict odor flow around the pecten via the relevant Reynolds numbers. The comb-like structure amplified the odor flow velocity similar to an amplifier, transporting the odor flow of increased velocity to the micron pecten sensilla, improving transport efficiency of the odor flow. The staggered arrangement of the pecten sensilla generated a vortex, improving contact duration between pecten sensilla and odorant molecules. Thus, the pecten fine structure was likely acting as an effective comb with non-smooth teeth for the transport and capture of odorant molecules.
基金National Natural Science Foundation of China (Grant Nos.51835006,51325501 and 51675220)Program for JLU Science and Technology Innovative Research Team (Grant No. 2017TD-04)Interdisciplinary research funding program for doctoral of Jilin University [Grant No. 10183201827].
文摘Recently,micro-vibrational perception mechanisms of nocturnal arthropods such as scorpions and spiders are attracting increasingly more attention and research.The relevant micro-vibrational receptors are exquisite,in terms of their comprehensive performance such as sensitivity,stability,high anti-interference,and ultralow-power consumption.In this work,we find the Basitarsal Compound Slit Sensilla (BCSS) of scorpion (Heterometrus petersii) are composed of the crack-shaped slits as mechanosensory structure and can efficiently detect substrate-borne vibrational signal in complex natural environment.The study on microstructures and mechanical properties of tissue phases constituting the BCSS reveals that the strategy of tessellation is used to make crack-shaped slit amplify the tiny mechanical signal.In addition,the magnitude-frequency characteristics of electrophysiological signals caused by vibration stimulation with different frequencies indicate that the scorpion is sensitive to micro-vibrational signals at a certain frequency range.Meanwhile,the vibrational perception mechanism based on geometrical amplification and resonance is proposed to explain how scorpions detect the tiny biotic vibrational signal efficiently in noise environment.This finding not only promotes our further understanding of ultra-sensitive mechanism of the vibrational receptors,but also provides biological inspiration for the next generation of mechanosensor for a broad range of applications.
基金co-supported by the National Natural Science Foundation of China(No.51775452)Fundamental Research Funds for the Central Universities,China(Nos.2682019CX35 and 2018GF02)Planning Project of Science&Technology Department of Sichuan Province,China(No.2019YFG0353).
文摘Fault diagnosis is vital in manufacturing system.However,the first step of the traditional fault diagnosis method is to process the signal,extract the features and then put the features into a selected classifier for classification.The process of feature extraction depends on the experimenters’experience,and the classification rate of the shallow diagnostic model does not achieve satisfactory results.In view of these problems,this paper proposes a method of converting raw signals into twodimensional images.This method can extract the features of the converted two-dimensional images and eliminate the impact of expert’s experience on the feature extraction process.And it follows by proposing an intelligent diagnosis algorithm based on Convolution Neural Network(CNN),which can automatically accomplish the process of the feature extraction and fault diagnosis.The effect of this method is verified by bearing data.The influence of different sample sizes and different load conditions on the diagnostic capability of this method is analyzed.The results show that the proposed method is effective and can meet the timeliness requirements of fault diagnosis.
基金supported by the National Natural Science Foundation of China(62033010)Aeronautical Science Foundation of China(2019460T5001)。
文摘It is quite often that the theoretic model used in the Kalman filtering may not be sufficiently accurate for practical applications,due to the fact that the covariances of noises are not exactly known.Our previous work reveals that in such scenario the filter calculated mean square errors(FMSE)and the true mean square errors(TMSE)become inconsistent,while FMSE and TMSE are consistent in the Kalman filter with accurate models.This can lead to low credibility of state estimation regardless of using Kalman filters or adaptive Kalman filters.Obviously,it is important to study the inconsistency issue since it is vital to understand the quantitative influence induced by the inaccurate models.Aiming at this,the concept of credibility is adopted to discuss the inconsistency problem in this paper.In order to formulate the degree of the credibility,a trust factor is constructed based on the FMSE and the TMSE.However,the trust factor can not be directly computed since the TMSE cannot be found for practical applications.Based on the definition of trust factor,the estimation of the trust factor is successfully modified to online estimation of the TMSE.More importantly,a necessary and sufficient condition is found,which turns out to be the basis for better design of Kalman filters with high performance.Accordingly,beyond trust factor estimation with Sage-Husa technique(TFE-SHT),three novel trust factor estimation methods,which are directly numerical solving method(TFE-DNS),the particle swarm optimization method(PSO)and expectation maximization-particle swarm optimization method(EM-PSO)are proposed.The analysis and simulation results both show that the proposed TFE-DNS is better than the TFE-SHT for the case of single unknown noise covariance.Meanwhile,the proposed EMPSO performs completely better than the EM and PSO on the estimation of the credibility degree and state when both noise covariances should be estimated online.
