- 标题
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- 实验方案
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Cowpea-structured PVDF/ZnO Nanofibers Based Flexible Self-powered Piezoelectric Bending Motion Sensor Towards Remote Control of Gestures
摘要： Interactive human-machine interface (iHMI) is a bridge connecting human beings and robots, which has an important requirement for perceiving the change of pressure and bending angle. Here, we designed a flexible self-powered piezoelectric sensor (PES) based on the cowpea-structured PVDF/ZnO nanofibers (CPZNs) for remote control of gestures in human-machine interactive system. Due to the synergistic piezoelectric effect of hybrid PVDF/ZnO and the flexibility of polymer, this PES exhibited excellent bending sensitivity of 4.4 mV deg-1 ranging widely from 44 ° to 122 °, fast response time of 76 ms, and good mechanical stability. Besides, the PES could operate under both bending and pressing mode, show ultrahigh pressing sensitivity of 0.33 V kPa-1, with response time of 16 ms. When integrated in iHMI, the PES could be conformably covered on different curve surfaces, demonstrated accurate bending angle recording and fast recognition for realizing intelligent human-machine interaction. On this basis, the application of remote control of robotic hand was successfully realized in form of acting the same gesture as human hand synchronously. This CPZNs-based self-powered PES is distinct and unique in its structure and fundamental mechanism, and exhibits a prospective potential application in iHMI.
关键词： human-machine interaction,cowpea-structured nanofiber,bending monitoring,self-powered,PVDF/ZnO
更新于2025-09-23 15:21:01
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1579 NM Fiber Laser Source for Spaceborne Monitoring of Carbon Dioxide
摘要： We report on the development of a 1579 nm pulsed fiber laser source with high peak-power, intended to be used as a lidar source for CO2 monitoring from space. We first discuss water-vapor sensitivity of spaceborne CO2 measurements by lidar and point the interest of the 1579 nm wavelength with that respect. Then we detail the current development status of the pulsed fiber laser source.
关键词： CO2 monitoring,lidar,1579 nm,spaceborne,fiber laser
更新于2025-09-23 15:21:01
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Highly Linear and Stable Flexible Temperature Sensors Based on Lasera??Induced Carbonization of Polyimide Substrates for Personal Mobile Monitoring
摘要： Wearable on-skin electronic devices that can monitor temperature in real time are of significant interest for personalized mobile health monitoring. Here, a flexible temperature sensor directly patterned by laser-induced carbonization on Kapton polyimide films integrated with flexible printed circuit boards is reported. The proposed sensor design possessing high resistance values exhibits high-linear and stable response to temperatures when integrated with flexible printed circuit boards (FPCBs) to enable continuous monitoring. The anisotropic conductive film bonding technique is used to obtain the stable real-time monitoring data under various complex environments. The sensor integration with a wearable patch based FPCB establishes conformal contacts with human skin and allows wireless sensing capabilities smoothly in real time. This kind of approach can enable multifunctional sensors to be directly laser patterned on FPCBs without any additional interfacing.
关键词： real-time monitoring,FPCB,laser-induced carbonization,temperature sensors,biomedical devices
更新于2025-09-23 15:21:01
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<i>(Invited)</i> Fluid Spectroscopy with Piezoelectric Ultrasound MEMS Transducers
摘要： In this work, Piezoelectric Micromachined Ultrasound Transducers (PMUTs) are explored as a potential MEMS solution for fluid property monitoring. PZT based PMUTs fabricated with three different diameters—1000 μm, 500 μm, 250 μm—showing in-air resonant frequencies between 100 kHz to 2 MHz are tested in water-glycerol mixtures with glycerol concentrations varying between 0% to 80% in both static and dynamic conditions. Spectral shifts of fluid environment are PMUT vibrations with changing quantitatively related to the density and viscosity of the fluid. The density sensitivity of the PMUTs is found to increase from 27 Hz/kg.m-3 for 1000 μm to 365 Hz/kg.m-3 for 250 μm, which is in close agreement with theoretical expectations. Similarly, viscosity sensing is also explored using PMUT arrays. A through-the-fluid ultrasound transmission architecture is proposed for a potential fluid property sensor that can fill the gap of miniature sensors for sensing physical properties of various fluids.
关键词： fluid property monitoring,viscosity,density,Piezoelectric Micromachined Ultrasound Transducers,PMUTs
更新于2025-09-23 15:21:01
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Study on subsidence monitoring technology using terrestrial 3D laser scanning without a target in a mining area: an example of Wangjiata coal mine, China
摘要： When using a Terrestrial 3D laser scanning (TLS) to monitor the mining subsidence in a mining area, the conventional methods are to set up the public target manually, or to set up the ground control network in advance. However, these have the disadvantages of high labor intensity and low efficiency. In order to overcome the shortcomings of the conventional methods, this paper presents the subsidence monitoring method using TLS without a target in the mining area. Feature points are used to splice the multi-station point clouds in the same phase, and a few station coordinates are used to uniformly transform the multiphase data into a geodetic coordinate system. Afterwards, the surface digital elevation model (DEM) is established by using the point clouds after coordinate transformation, and the dynamic subsidence value and subsidence basin during the period of observation are obtained by DEM subtraction. Compared to traditional methods, this method simplifies the field measurement process, reduces the labor intensity, and transfers the main work to the internal industry. It is suitable for surface subsidence monitoring with a harsh external environment and complicated topographic conditions. Surface deformation values are important basic data for mining area subsidence parameters acquisition, mining area environmental assessment, land reclamation, and ecological restoration. As a consequence, it is of great value to popularize and apply in mining area for subsidence monitoring.
关键词： Coordinate transformation,Registration,Subsidence basin,3D laser scanning technology,Deformation monitoring
更新于2025-09-23 15:21:01
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Infrared Camera-Based Non-contact Measurement of Brain Activity From Pupillary Rhythms
摘要： Pupillary responses are associated with affective processing, cognitive function, perception, memory, attention, and other brain activities involving neural pathways. The present study aimed to develop a noncontact system to measure brain activity based on pupillary rhythms using an infra-red web camera. Electroencephalogram (EEG) signals and pupil imaging of 70 undergraduate volunteers (35 female, 35 male) were measured in response to sound stimuli designed to evoke arousal, relaxation, happiness, sadness, or neutral responses. This study successfully developed a real-time system that could detect an EEG spectral index (relative power: low beta in FP1; mid beta in FP1; SMR in FP1; beta in F3; high beta in F8; gamma P4; mu in C4) from pupillary rhythms using the synchronization phenomenon in harmonic frequency (1/100 f) between the pupil and brain oscillations. This method was effective in measuring and evaluating brain activity using a simple, low-cost, noncontact system, and may be an alternative to previous methods used to evaluate brain activity.
关键词： harmonic frequency,pupil size variation,brain activity,vital sign monitoring,non-contact measurement
更新于2025-09-23 15:21:01
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Discerning Localized Thermal Heating from Mechanical Strain Using an Embedded Distributed Optical Fiber Sensor Network
摘要： Prior research has demonstrated that distributed optical fiber sensors (DOFS) based on Rayleigh scattering can be embedded in carbon fiber/epoxy composite structures to rapidly detect temperature changes approaching 1000°C, such as would be experienced during a high energy laser strike. However, composite structures often experience mechanical strains that are also detected during DOFS interrogation. Hence, the combined temperature and strain response in the composite can interfere with rapid detection and measurement of a localized thermal impulse. In this research, initial testing has demonstrated the simultaneous response of the DOFS to both temperature and strain. An embedded DOFS network was designed and used to isolate and measure a localized thermal response of a carbon fiber/epoxy composite to a low energy laser strike under cyclic bending strain. The sensor interrogation scheme uses a simple signal processing technique to enhance the thermal response, while mitigating the strain response due to bending. While our ultimate goal is rapid detection of directed energy on the surface of the composite, the technique could be generalized to structural health monitoring of temperature sensitive components or smart structures.
关键词： smart structures,distributed optical fiber sensors,temperature sensors,structural health monitoring,high energy radiation,polymer matrix composites,strain sensors,strain compensation
更新于2025-09-23 15:21:01
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An On-Line Low-Cost Irradiance Monitoring Network with Sub-Second Sampling Adapted to Small-Scale PV Systems
摘要： Very short-term solar forecasts are gaining interest for their application on real-time control of photovoltaic systems. These forecasts are intimately related to the cloud motion that produce variations of the irradiance field on scales of seconds and meters, thus particularly impacting in small photovoltaic systems. Very short-term forecast models must be supported by updated information of the local irradiance field, and solar sensor networks are positioning as the more direct way to obtain these data. The development of solar sensor networks adapted to small-scale systems as microgrids is subject to specific requirements: high updating frequency, high density of measurement points and low investment. This paper proposes a wireless sensor network able to provide snapshots of the irradiance field with an updating frequency of 2 Hz. The network comprised 16 motes regularly distributed over an area of 15 m × 15 m (4 motes × 4 motes, minimum intersensor distance of 5 m). The irradiance values were estimated from illuminance measurements acquired by lux-meters in the network motes. The estimated irradiances were validated with measurements of a secondary standard pyranometer obtaining a mean absolute error of 24.4 W/m2 and a standard deviation of 36.1 W/m2. The network was able to capture the cloud motion and the main features of the irradiance field even with the reduced dimensions of the monitoring area. These results and the low-cost of the measurement devices indicate that this concept of solar sensor networks would be appropriate not only for photovoltaic plants in the range of MW, but also for smaller systems such as the ones installed in microgrids.
关键词： pyranometer,irradiance monitoring network,very short-term solar forecasting,microgrids,cloud enhancement,wireless sensor network,lux-meter
更新于2025-09-23 15:21:01
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Drying-induced soil shrinkage and desiccation cracking monitoring with distributed optical fiber sensing technique
摘要： Monitoring of drying-induced volume shrinkage and desiccation cracking in clayey soils is of great importance in geological and geotechnical engineering. Compared with conventional strain monitoring methods providing discrete measurements, the Brilliouin optical time domain reflectometer (BOTDR) technique enables continuous measurement of the distributed strain generated along optical fibers. In this study, a physical model test is conducted to investigate the feasibility of monitoring drying-induced soil shrinkage and desiccation cracking using BOTDR. Three optical fibers with different surface protections (thermoplastic polyester elastomer (TPEE) jacket, nylon jacket, and acrylate coating) are tested and compared. Experimental results validate that BOTDR is applicable for the direct strain monitoring of desiccation cracking soils. Monitored strain values are strongly influenced by water content, soil cracking, and fiber types. The strain measured by the optical fiber reaches only several micro strains when the soil is over-saturated, gradually increases with the decreasing water content and the increasing soil-fiber interfacial shear stresses, and drops rapidly after the occurrence of decoupling between fiber and soil resulting from the mature development of desiccation cracks. The optical fiber with acrylate coating is not suitable because of its fragility and the poor interfacial coupling with the soil. Optical fibers covered with TPEE jacket or nylon jacket are both applicable for soil strain monitoring, with the former one more sensitive to water content variations. The study is the first attempt to apply the BOTDR technique for the direct and continuous monitoring of drying-induced soil shrinkage and desiccation cracking process. It is expected bring new insights into the fundamental understanding of volumetric shrinkage and desiccation cracking in clayey soils.
关键词： Brilliouin optical time domain reflectometer (BOTDR),Desiccation crack,Volumetric shrinkage,Strain monitoring,Optical fiber sensing
更新于2025-09-23 15:21:01
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Smartphone APP for Continuous Observation of Pollution Levels Due to Particulate Matter Measured by Laser Mie Scattering
摘要： The article is a work intended to meet the need for mobile monitoring of polluted air comprising of excessive fine particulate matter by a compact cellular phone application. The description is about the setting up of a laser scattering compact module with an Arduino like circuit board interface and the display on the handheld smart phone through Bluetooth while the person is on the move. Giving an introduction to the Mie Scattering method with a laser beam exposed to ambient (polluted) air through a miniature blower. With an introduction to the principles of Mie Scattering of laser beam, the work has resulted in a portable set-up which is worn by any one and the levels of particulate matter viewed on one’s smart phone through an ‘‘app’’ developed for this purpose.
关键词： Particulate matter,Mie Scattering of light,Pollution monitoring,MIT App. inventor,PM2.5 and PM10
更新于2025-09-23 15:21:01