For the first time, a deformable liquid metal patch, which is loaded with an air cavity underneath, is proposed for designing an air pressure-detecting antenna. Both the liquid metal (EGaIn) and air cavity of the antenna structure are constructed inside a soft and deformable polydimethylsiloxane (PDMS) substrate. Since liquid metal is highly dense, a PDMS pillar is tactfully embedded into the air cavity

Since the well-established navigation systems such as GPS are ineffective in indoor environments, research into developing novel indoor positioning technologies has emerged in recent years. While several technologies are being investigated, a practical and reliable indoor positioning system is yet to emerge. Indoor positioning using light signals holds a great potential to provide a reliable solution

Since the launch of the first consumer grade EEG measuring sensors ‘NeuroSky Mindset’ in 2007, the market has witnessed an introduction of at least one new product every year by competing manufacturers, which include NeuroSky, Emotiv, interaXon and OpenBCI. There are numerous variations in the make and versions, but these products clearly share the key selling points of affordability, portability,

In the last two decades, visual sensor networks have been developed to gather visual data from different monitoring scenarios, directly contributing to the maturation of the Internet of Things (IoT) applications landscape. Such developments have evolved according to the releasing of new hardware platforms for the construction of sensor nodes, as well as the availability of low-power compatible cameras

Lactate, a key metabolite of the anerobic metabolic pathway serves as a biomarker for lactic acidosis in clinical diagnostics. A variety of electrochemical biosensors have been exploited for the determination of lactate. Here we describe an improved electrochemical lactic acid biosensor that utilizes self-assembled monolayers (SAMs) of cysteamine-modified gold nanoparticles (AuNPs) on flexible tungsten

To understand and improve the translocation dynamics of nanopore based sensors, we studied theoretically the translocation of DNA molecules and compared them with experimental results. In our experimental studies, we used conically shaped track-etched polymer (i.e., PET) membrane and built our model based on its physical properties. Simulations were conducted by varying the surface charges of the nanopore

In the present work, we have developed a solution-processable poly (2,5-bis (3-tetradecylthiophen 2yl) thieno(3,2b) thiophene) (PBTTT-C14) based organic thin film transistor, for possible selective sensing the toxic ammonia (NH 3 ) gas at 25°C. This thin-film transistor based sensor makes use of PBTTT-C14 polymer as an organic channel that exhibits highly responsive (>61%) behavior at different levels

In this research, response of various nanostructures of cobalt ferrite including nanoparticles, nanorods and porous nanoparticles to methanol is investigated and compared. The nanostructures were prepared using a hydrothermal method and their crystallographic, morphologic and magnetic characteristics were studied by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and vibrating

Boron nitride nanowires (BNNWs) with high purity and a long-straight fashion are synthesized via ball milling and annealing technique at 1150°C successfully. These nanowires have an average length of more than $50\mu \text{m}$ with diameter 100 nm. The results of characterization showed that the main elements of the nanowires are boron and nitrogen, which molar ratio of B:N is close to 1 indicating

The development of vibration control with smart fluids within flexible structures has been of significant interest in recent times. Although much research has been done on structures with embedded electrorheological fluids (ERF) and magnetorheological fluids (MRF), there has been a little investigation into localizing smart fluids under micro-structures. Research into the damping of micro-structures

A simple, passive, single-element ultrasonic transducer is proposed for non-invasive measurements. Operating the transducer at different resonant modes allows the adaptation of the emitted sound pattern to various requirements. The emitted sound field is simulated and experimentally characterized. We demonstrate the suitability of the transducer prototype for non-invasive continuous level measurement

Inkjet-printing is a promising low-cost fabrication technique capable of depositing functional materials with micrometer resolution, making this technique attractive for the fabrication of deformable sensors. Despite all the possible promising applications, no examples of inkjet-printed strain sensors array able to map substrate surface deformation have been proposed yet. On the base of these premises

The work reported in this paper aims at developing a simple one sensor based system to achieve condition monitoring of NFR (Northeast Frontier Railway, India) trains. Vibration of a railway track under train in motion provides important information about the train.To capture the vibration of a track under train in motion, vibration sensor ADXL335 is selected, as it is a reliable vibration sensor. Moreover

In this paper, a thin film based Thermoresistive Micro Calorimetric Flow (TMCF) sensor by using a $0.35~\mu \text{m}$ 2P4M CMOS MEMS technology is designed, fabricated and tested. The developed $1.6~\mu \text{m}$ thick thin film CMOS TMCF sensor shows a maximum normalized sensitivity of 103 mV/(m/s)/mW with respect to the input heating power and a wide dynamic flow range of 0 ~ 19.4 m/s. The high sensitivity

In this paper, we present a new type of low cost force localized interaction sensor dedicated to robot interactive sensing system. The design of the sensor is based on mechanical deformation and mathematical models. It includes the capability to be integrated easily in robotic limbs. This sensing system is based on the coupled results obtained from six well-located force sensors in order to measure

This article focuses on the prediction of the vibration frequency response of handheld probes. A novel approach that involves machine learning and readily available data from probes was explored. Vibration probes are efficient and affordable devices that provide information about testing airborne sound insulation in building acoustics. However, fixing a probe to a vibrating surface downshifts sensor

MEMS-IMUs have an extensive application in multifarious studies, as well as industrial and commercial areas. It is crucial to diminish their intrinsic errors in a suitable calibration procedure. In this paper, a novel calibration procedure was proposed for Inertial Measurement Units (IMUs) on a turntable. A general nonlinear model of the IMU output including the effects of bias, scale factor, misalignment

This paper reports a novel MEMS gas flow sensor that relies on the temperature drop induced when the gas flows over an electrically heated MEMS triple-beam resonator. Modelling, simulation and characterization of the sensor has been undertaken to quantify the temperature-induced shift of resonance frequency of the resonator, which can be directly related to the rate of gas flow over the heated resonator

104 MHz surface acoustic wave sensors, functionalized with two polypyrrole (PPy) imprinted polymers, were designed for lead ion detection in liquid media. The main difference between the two ionic imprinted polymers (IIP) is related to the nature of the chelating agent: L-Cysteine (L-Cys) for the former and acrylic acid (AA) for the latter. Performances of the IIPs based sensors were compared in terms

The application of self-contained field-portable, internet connected spectroscopic diagnostics in food analysis using a fibre endoscopic smart fluorimeter is reported. A UV-induced fluorescence is used to measure the quality of olive oils, distinguishing between extra virgin and others within a smartphone platform. When excited at $\lambda \sim ~370$ nm, the extra virgin olive oil fluoresces red at

The facile enhancement of the optical photocurrent in gallium nitride (GaN) ultraviolet (UV) photodetectors was realized by applying an in-situ curing technique to polymer lenses on a GaN surface. To fabricate plano-convex polymer lenses that focus incident UV light, a prepolymer was dropped directly onto the GaN surface and cured at room temperature to induce UV light refraction. When the incident

Due to the recent rapid industrialization and urbanization across the world, chemicals are released into the environment at an unprecedented rate. Gas sensors, in particular, interferometric based devices represent an important toolkit for air quality monitoring. Amongst different interferometers, linear variable filter (LVF) holds the promise of a fixed optical component that can be operated under

A tunable diode laser absorption spectroscopy (TDLAS) tomographic system was proposed via utilizing the wavelength modulation spectroscopy (WMS) method and distributions of temperature and specie concentrations in the dynamic flames were simultaneously reconstructed for the first time. A five-view fan beam tomographic sensor was applied to capture the absorption spectrum along the laser paths across

Although the clock synchronization is of utmost importance in communications, it is quite difficult to achieve in practice. Consequently, the asynchronous effect emerges as a critical problem for all pulse-position modulation (PPM) systems. In this paper, the impact of the sampling-period misalignment is studied and evaluated. A new analytical model is established to govern the misalignment between

In this paper, the design methodology of a microstrip angular displacement sensor based on an impedance transformer with a quasi-Chebyshev frequency response is proposed. This sensor with impedance transforming function can realize the angular displacement detection by bandwidth sensing, and matching sensing simultaneously. The insertion loss in stopband achieves 24.9 dB to 32.6 dB with an average

Fiber Bragg Gratings (FBGs) are known for their high sensitivity towards strain and temperature variation. In this manuscript, the strain sensing property of FBG is utilized and explored for measuring weight using a common binocular shaped cantilever type load cell. The shift in Bragg wavelength due to load application is converted into optical power variation using edge filter detection technique

A novel refractive index sensing using the tapered single mode fiber (TSMF) is proposed based on the chaotic correlation fiber loop ring down system (FLRDs). A chaotic fiber laser is used to drive the fiber loop cavity. The performance of the proposed TSMF chaotic correlation FLRDs refractive index sensing was demonstrated by measuring the ring down time of the peaks of correlation coefficient of the

In this paper a new method for the detection of optical phase in passive homodyne interferometers, with high accuracy and wide dynamic range is presented. Unlike the traditional and more recent methods, which use between 3 and 6 harmonic components to calculate the modulation index, the proposed method uses only 2 harmonic components. Because of this, the method has higher accuracy in the presence

A light intensity-modulated optical fiber sensor for continuous level measurement is proposed and demonstrated. The sensor is constructed by vertically arranging groups of fibers on the oblique surface which reflects all the incident light when the fibers are in the air but a small proportion of light when the fibers are immersed in the liquid. In order to implement easy modulation and detection, the

This paper presents a mathematical model for the interrogation of long period grating (LPG) fiber optical sensor. The mathematical model is simple and robust, and it is based on an electrical harmonic analysis. The model calculates the harmonic amplitude equations in the electrical domain of a wavelength modulated optical signal as a function of all the spectral parameters of the LPG. In addition,

In this paper the influences of the structured parameters, namely, metal layer thickness, polished depth, macrobending radius and polished angle on the refractive index sensing performances for the side-polished macrobending plastic optical fibers (POFs) based surface plasmon resonance (SPR) sensors were investigated. A simple and controllable rotary grinding technique was introduced to fabricate the

Creatinine (CR) produced through the muscle metabolism acts as biomarker to monitor the kidney functioning of the human body. In this study, a successful effort has been made to develop a fast and easy detection method for the monitoring of CR concentration in an aqueous solution as well as in the artificial urine sample. The sensor has been developed over a lossy mode resonance (LMR) based optical

The sink hole problem is a critical issue for data collection in wireless sensor networks. Recent research has indicated that the mobility of actuators in wireless sensor actuator networks (WSANs) alleviates the sink hole problem. However, mobile actuator-based data collection may result in unsatisfactory data gathering delay, which is not acceptable for delay-sensitive real time applications. Thus

Three different microbalances were coated with aptamers with thiol termination designed to attach to the capsid proteins of the whole Zika virus. The first microbalance was a 5 MHz commercial AT-cut (QSense) quartz microbalance that showed 1 Hz/ng sensitivity with minimum detectable signal (MDS) of 1 ng. The second sensor was a 10 MHz AT-cut quartz sensor that was extracted from a communication filter

In this paper, a new diffusion-reaction equation was formulated to research the influences of grain radius on the transients of gas transport and gas sensitivity for porous thin film medium semiconducting metal oxide gas sensor, based on the phenomenon that a target gas diffuses in the sensing film via Knudsen diffusion and reacts with adsorbed oxygen on the pore surfaces following Langmuir adsorption

This paper presents a low-power high-sensitivity CMOS read-out integrated circuit (ROIC) realized in a 0.13 $ {\mu }\text{m}$ CMOS technology for cyanobacteria detection and monitoring with the current sensing capability of nano-ampere levels. The proposed CMOS ROIC consists of a current-conveyor transimpedance amplifier (CC-TIA) and a 9 bit successive approximation register (SAR) analog-to-digital

A novel resonant noise matching technique is proposed to improve the sensitivity and output SNR of ultrasound receivers. Diverse from the power matching, the resonant noise matching technique proposed in this paper applies resonant LC networks to raise the transducers’ input impedance to a high impedance. As a consequence, in addition to the function of improving the output signal strength, the prominent

In this paper, we present a machine learning model to estimate the blood pressure (BP) of a person using only his photoplethysmogram (PPG) signal. We propose algorithms to better detect some critical points of the PPG signal, such as systolic and diastolic peaks, dicrotic notch and inflection point. These algorithms are applicable to different PPG signal morphologies and improve the precision of feature

A new set of morphological characteristics of Phonocardiogram (PCG) signal is presented for recognition of first ( ${S}_{{1}}$ ) and second ( ${S}_{{2}}$ ) heart sounds (HSs). Initially, variational mode decomposition on PCG signal generates a set of amplitude and frequency modulated narrow band-limited components (NBCs) and Hilbert transformation of these NBCs comprehends its complex plane analytic

Dual-circular polarimetric (DCP) high-resolution range profile (HRRP) provides similar target information to the full polarimetric HRRP and has the same data volume as the dual-linear polarimetric HRRP, thus it is significant to investigate the capability of DCP HRRP for target recognition. In this paper, a novel feature extraction method is proposed for the DCP HRRP-based target recognition. First

With recent advances in sensor technology, multispectral systems are becoming increasingly attractive for intelligence, surveillance, and reconnaissance applications. Fusing information from multiple imaging modalities is a major task for such systems. Combining feature maps obtained from multiple deep neural network pipelines demonstrates promising performance for object detection and tracking. However

In this paper, a new response approximation model for quadrant detector is proposed based on a BP Neural Network by employing different training algorithms. A total of 1001 data points are gathered to train and test the proposed network. Through optimal configuration, the network with 1 hidden layer and 8 hidden neurons with Log-sigmoid transfer functions in the hidden layer is determined to have the

Advancements in the synchrosqueezing transform as a postprocessing time–frequency method have received considerable attention in the past few decades for the analysis of nonstationary signals. Many studies have focused on improving the accuracy of the estimated instantaneous frequency (IF). In some fields, the IF spectra of signals exhibit fast varying behavior or even some times parallel to the frequency

Smartphones are a promising platform for continuous monitoring of human behavior. However, the ability to capture people’s behavioral patterns in-the-wild is a challenge, as the user’s behavior and physical activities can vary, given the variability of settings and environments. Modeling and understanding of human activity in-the-wild must not overlook a user’s behavioral context, which is just as

Fusion techniques are employed in pedestrian tracking to achieve more accurate and robust tracking systems. A common approach is to fuse Inertial Navigation System (INS), worn by a pedestrian, with a radio-based system to complement each other and mitigate their shortcomings. Despite the increased accuracy achieved in the state-of-the-art approaches, the deployment complexity and cost of these tracking

Passive bistatic radars have been reported to detect and track drones, general aviation aircraft, and civil aviation aircraft extensively. However, localization performance is limited by the poor azimuth estimation. On the other hand, lots of digital television broadcasting transmitters have sprung up, and they work at different frequencies. In order to utilize the spatial diversity of the transmitters

Large-scale microelectrode arrays offers enhanced spatiotemporal resolution in electrophysiology studies. In this paper, we discuss the design and performance of an electrochemical detector array which is capable of 1024-ch parallel cyclic voltammetry. The electrochemical detector is fabricated using a custom-designed CMOS chip, which integrates both the circuity and on-chip microelectrode array, to

Adaptive generalized sidelobe cancelers (GSCs) have been widely used to enhance the desired signal and instantaneously suppress interference signal and noise. However, the GSC beamforming method must know the direction of arrival (DOA) of the desired signal in advance. In this paper, we consider the case of a sensor array application in free-field air in which the target signal source is moving, leading

Dispersive acoustic metamaterials (AMMs) with graded refractive index is promising in acoustic sensing enhancement by providing acoustic rainbow trapping (ART) effect. However, previous solutions to this type of AMMs are based on 2D unit cells that require infinite or very large size in the third dimension; they cannot integrate with conventional acoustic sensors without deteriorating the ability of

In this work, a gain-enhanced Vivaldi antenna is proposed, which is integrated with the transceiver on a printed circuit board. The gain and the radiation pattern are improved with the addition of the optimization strips in front of the flare without extending the antenna width. Finally, conventional and gain-enhanced Vivaldi antennas are fabricated and applied to the through-wall radar(TWR) system

Multisensor fusion of air pollutant data in smart buildings remains an important input to address the well-being and comfort perceived by their inhabitants. An integrated sensing system is part of a smart building where real-time indoor air quality data are monitored round the clock using sensors and operating in the Internet-of-Things (IoT) environment. In this work, we propose an air quality management

This paper extends the ‘go-with-the-flow’ method to explore enclosed environments, like oil reservoirs, pipe lines that transport liquids, and industrial tanks for processing chemicals, where sensing nodes cannot establish communication with the external world. Nonetheless, large quantities of highly miniaturized, thus power-constrained sensor nodes are injected into these environment and flow through

In vivo and in vitro studies of differential continuous wave photoacoustic spectroscopy (DCW-PAS) for non-invasive blood glucose monitoring were performed. The DCW-PAS technique utilizes amplitude modulation of dual wavelengths of light to determine changes in glucose concentration. The study compared DCW-PAS measurements with results from invasive blood glucose sensor measurements during oral glucose

An accurate close-range positioning and navigation system is the key to autonomous cruise and the fine operations of multi-rotor UAVs. In this paper, a dynamic electromagnetic positioning system is designed and implemented to accurately navigate a UAV to a very small landing zone. The system is composed of three quasi-static electromagnetic field generators (EGs) installed around the landing zone,

Drowsiness is a common human physiological response. Research suggests that insufficient sleep results in low energy levels, various negative physiological and psychological effects on the body, and abnormal cognitive functioning. Studies have predominantly focused on driving while drowsy, using brainwave measurement and facial detection techniques to address this topic, whereas few have discussed

In this paper, a new path planning algorithm is developed to address the problem of persistent and cooperative coverage using a group of robots in a complex environment. Previous works have mainly used geometric division to achieve collaborative coverage search, but ignored the environmental complexity and the path length difference of each robot. In contrast, this paper presents a novel strategy for

Discriminative Correlation Filter (DCF) based trackers achieve superior performance with continuous conceptual improvement in the tracking field. By now, traditional DCF based trackers suppose that the tracked target is rigid and could be represented by an axis-aligned rectangular box well. Those trackers suffer from object deformation, irregular object shape and partial occlusion where the target

Soil harbours innumerable microorganisms, nutrients, and other crucial elements, it anchors vegetation and supplies it with the primary factors that make agriculture possible. Soil health is determined by quantifying nutrients and physical parameters that are required to be in optimum range depending on the cropping pattern. In line with this, the current work presents an integrated, low-cost, microfluidic-based

Integrated GPS receivers have become a basic module in today’s mobile devices. While serving as the cornerstone for location based services, GPS modules have a serious battery drain problem due to high computation load. This paper aims to reveal the impact of key software parameters on GPS energy consumption, by establishing an energy model for a standard GPS receiver architecture as found in both

A silicon-based compact comb-like asymmetric grating is proposed as a thermally stable optical filter for label-free sensing applications. The device is designed and fabricated with a cavity section introduced between the two grating regions which are partially etched in the lateral direction to ensure the nonzero coupling of the fundamental and first-order modes in the propagation and counter-propagation