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19 pages, 6427 KiB

Open AccessArticle

A Measurement Method for Large Parts Combining with Feature Compression Extraction and Directed Edge-Point Criterion

by Wei Liu, Yang Zhang, Fan Yang, Peng Gao, Zhiguang Lan, Zhenyuan Jia and Hang Gao

Sensors 2017, 17(1), 40; https://doi.org/10.3390/s17010040 - 26 Dec 2016

Cited by 6 | Viewed by 5134

Abstract

High-accuracy surface measurement of large aviation parts is a significant guarantee of aircraft assembly with high quality. The result of boundary measurement is a significant parameter for aviation-part measurement. This paper proposes a measurement method for accurately measuring the surface and boundary of [...] Read more.

High-accuracy surface measurement of large aviation parts is a significant guarantee of aircraft assembly with high quality. The result of boundary measurement is a significant parameter for aviation-part measurement. This paper proposes a measurement method for accurately measuring the surface and boundary of aviation part with feature compression extraction and directed edge-point criterion. To improve the measurement accuracy of both the surface and boundary of large parts, extraction method of global boundary and feature analysis of local stripe are combined. The center feature of laser stripe is obtained with high accuracy and less calculation using a sub-pixel centroid extraction method based on compress processing. This method consists of a compressing process of images and judgment criterion of laser stripe centers. An edge-point extraction method based on directed arc-length criterion is proposed to obtain accurate boundary. Finally, a high-precision reconstruction of aerospace part is achieved. Experiments are performed both in a laboratory and an industrial field. The physical measurements validate that the mean distance deviation of the proposed method is 0.47 mm. The results of the field experimentation show the validity of the proposed method. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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14 pages, 7101 KiB

Open AccessArticle

Three-Dimensional Object Recognition and Registration for Robotic Grasping Systems Using a Modified Viewpoint Feature Histogram

by Chin-Sheng Chen, Po-Chun Chen and Chih-Ming Hsu

Sensors 2016, 16(11), 1969; https://doi.org/10.3390/s16111969 - 23 Nov 2016

Cited by 24 | Viewed by 8301

Abstract

This paper presents a novel 3D feature descriptor for object recognition and to identify poses when there are six-degrees-of-freedom for mobile manipulation and grasping applications. Firstly, a Microsoft Kinect sensor is used to capture 3D point cloud data. A viewpoint feature histogram (VFH) [...] Read more.

This paper presents a novel 3D feature descriptor for object recognition and to identify poses when there are six-degrees-of-freedom for mobile manipulation and grasping applications. Firstly, a Microsoft Kinect sensor is used to capture 3D point cloud data. A viewpoint feature histogram (VFH) descriptor for the 3D point cloud data then encodes the geometry and viewpoint, so an object can be simultaneously recognized and registered in a stable pose and the information is stored in a database. The VFH is robust to a large degree of surface noise and missing depth information so it is reliable for stereo data. However, the pose estimation for an object fails when the object is placed symmetrically to the viewpoint. To overcome this problem, this study proposes a modified viewpoint feature histogram (MVFH) descriptor that consists of two parts: a surface shape component that comprises an extended fast point feature histogram and an extended viewpoint direction component. The MVFH descriptor characterizes an object’s pose and enhances the system’s ability to identify objects with mirrored poses. Finally, the refined pose is further estimated using an iterative closest point when the object has been recognized and the pose roughly estimated by the MVFH descriptor and it has been registered on a database. The estimation results demonstrate that the MVFH feature descriptor allows more accurate pose estimation. The experiments also show that the proposed method can be applied in vision-guided robotic grasping systems. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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19 pages, 4570 KiB

Open AccessArticle

In Vivo Neural Recording and Electrochemical Performance of Microelectrode Arrays Modified by Rough-Surfaced AuPt Alloy Nanoparticles with Nanoporosity

by Zongya Zhao, Ruxue Gong, Liang Zheng and Jue Wang

Sensors 2016, 16(11), 1851; https://doi.org/10.3390/s16111851 - 3 Nov 2016

Cited by 25 | Viewed by 6523

Abstract

In order to reduce the impedance and improve in vivo neural recording performance of our developed Michigan type silicon electrodes, rough-surfaced AuPt alloy nanoparticles with nanoporosity were deposited on gold microelectrode sites through electro-co-deposition of Au-Pt-Cu alloy nanoparticles, followed by chemical dealloying Cu. [...] Read more.

In order to reduce the impedance and improve in vivo neural recording performance of our developed Michigan type silicon electrodes, rough-surfaced AuPt alloy nanoparticles with nanoporosity were deposited on gold microelectrode sites through electro-co-deposition of Au-Pt-Cu alloy nanoparticles, followed by chemical dealloying Cu. The AuPt alloy nanoparticles modified gold microelectrode sites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and in vivo neural recording experiment. The SEM images showed that the prepared AuPt alloy nanoparticles exhibited cauliflower-like shapes and possessed very rough surfaces with many different sizes of pores. Average impedance of rough-surfaced AuPt alloy nanoparticles modified sites was 0.23 MΩ at 1 kHz, which was only 4.7% of that of bare gold microelectrode sites (4.9 MΩ), and corresponding in vitro background noise in the range of 1 Hz to 7500 Hz decreased to 7.5

μ V_{rms}

from 34.1

μ V_{rms}

at bare gold microelectrode sites. Spontaneous spike signal recording was used to evaluate in vivo neural recording performance of modified microelectrode sites, and results showed that rough-surfaced AuPt alloy nanoparticles modified microelectrode sites exhibited higher average spike signal-to-noise ratio (SNR) of 4.8 in lateral globus pallidus (GPe) due to lower background noise compared to control microelectrodes. Electro-co-deposition of Au-Pt-Cu alloy nanoparticles combined with chemical dealloying Cu was a convenient way for increasing the effective surface area of microelectrode sites, which could reduce electrode impedance and improve the quality of in vivo spike signal recording. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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13 pages, 5264 KiB

Open AccessArticle

Plantar Pressure Detection with Fiber Bragg Gratings Sensing System

by Tsair-Chun Liang, Jhe-Jhun Lin and Lan-Yuen Guo

Sensors 2016, 16(10), 1766; https://doi.org/10.3390/s16101766 - 22 Oct 2016

Cited by 39 | Viewed by 10436

Abstract

In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively [...] Read more.

In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively identify four foot types: neutral foot, cavus foot, supinated foot and flat foot. The plantar pressure signals are detected by only six FBGs, which are embedded in silicone rubber. The performance of the fiber optic sensing is examined and compared with a digital pressure plate of i-Step P1000 with 1024 barometric sensors. In the experiment, there are 11 participants with different foot types to participate in the test. The Pearson correlation coefficient, which is determined from the measured results of the homemade fiber-optic plantar pressure system and i-Step P1000 plantar pressure plate, reaches up to 0.671 (p < 0.01). According to the measured results from the plantar pressure data, the proposed fiber optic sensing system can successfully identify the four different foot types. Measurements of this study have demonstrated the feasibility of the proposed system so that it can be an alternative for plantar pressure detection systems. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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13 pages, 3137 KiB

Open AccessArticle

CCD-Based Skinning Injury Recognition on Potato Tubers (Solanum tuberosum L.): A Comparison between Visible and Biospeckle Imaging

by Yingwang Gao, Jinfeng Geng, Xiuqin Rao and Yibin Ying

Sensors 2016, 16(10), 1734; https://doi.org/10.3390/s16101734 - 18 Oct 2016

Cited by 12 | Viewed by 5374

Abstract

Skinning injury on potato tubers is a kind of superficial wound that is generally inflicted by mechanical forces during harvest and postharvest handling operations. Though skinning injury is pervasive and obstructive, its detection is very limited. This study attempted to identify injured skin [...] Read more.

Skinning injury on potato tubers is a kind of superficial wound that is generally inflicted by mechanical forces during harvest and postharvest handling operations. Though skinning injury is pervasive and obstructive, its detection is very limited. This study attempted to identify injured skin using two CCD (Charge Coupled Device) sensor-based machine vision technologies, i.e., visible imaging and biospeckle imaging. The identification of skinning injury was realized via exploiting features extracted from varied ROIs (Region of Interests). The features extracted from visible images were pixel-wise color and texture features, while region-wise BA (Biospeckle Activity) was calculated from biospeckle imaging. In addition, the calculation of BA using varied numbers of speckle patterns were compared. Finally, extracted features were implemented into classifiers of LS-SVM (Least Square Support Vector Machine) and BLR (Binary Logistic Regression), respectively. Results showed that color features performed better than texture features in classifying sound skin and injured skin, especially for injured skin stored no less than 1 day, with the average classification accuracy of 90%. Image capturing and processing efficiency can be speeded up in biospeckle imaging, with captured 512 frames reduced to 125 frames. Classification results obtained based on the feature of BA were acceptable for early skinning injury stored within 1 day, with the accuracy of 88.10%. It is concluded that skinning injury can be recognized by visible and biospeckle imaging during different stages. Visible imaging has the aptitude in recognizing stale skinning injury, while fresh injury can be discriminated by biospeckle imaging. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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12 pages, 4105 KiB

Open AccessArticle

Application of CCG Sensors to a High-Temperature Structure Subjected to Thermo-Mechanical Load

by Weihua Xie, Songhe Meng, Hua Jin, Chong Du, Libin Wang, Tao Peng, Fabrizio Scarpa and Chenghai Xu

Sensors 2016, 16(10), 1686; https://doi.org/10.3390/s16101686 - 13 Oct 2016

Cited by 1 | Viewed by 5950

Abstract

This paper presents a simple methodology to perform a high temperature coupled thermo-mechanical test using ultra-high temperature ceramic material specimens (UHTCs), which are equipped with chemical composition gratings sensors (CCGs). The methodology also considers the presence of coupled loading within the response provided [...] Read more.

This paper presents a simple methodology to perform a high temperature coupled thermo-mechanical test using ultra-high temperature ceramic material specimens (UHTCs), which are equipped with chemical composition gratings sensors (CCGs). The methodology also considers the presence of coupled loading within the response provided by the CCG sensors. The theoretical strain of the UHTCs specimens calculated with this technique shows a maximum relative error of 2.15% between the analytical and experimental data. To further verify the validity of the results from the tests, a Finite Element (FE) model has been developed to simulate the temperature, stress and strain fields within the UHTC structure equipped with the CCG. The results show that the compressive stress exceeds the material strength at the bonding area, and this originates a failure by fracture of the supporting structure in the hot environment. The results related to the strain fields show that the relative error with the experimental data decrease with an increase of temperature. The relative error is less than 15% when the temperature is higher than 200 °C, and only 6.71% at 695 °C. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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11 pages, 12693 KiB

Open AccessArticle

A Wireless and Batteryless Intelligent Carbon Monoxide Sensor

by Chen-Chia Chen, Gang-Neng Sung, Wen-Ching Chen, Chih-Ting Kuo, Jin-Ju Chue, Chieh-Ming Wu and Chun-Ming Huang

Sensors 2016, 16(10), 1568; https://doi.org/10.3390/s16101568 - 23 Sep 2016

Cited by 8 | Viewed by 6861

Abstract

Carbon monoxide (CO) poisoning from natural gas water heaters is a common household accident in Taiwan. We propose a wireless and batteryless intelligent CO sensor for improving the safety of operating natural gas water heaters. A micro-hydropower generator supplies power to a CO [...] Read more.

Carbon monoxide (CO) poisoning from natural gas water heaters is a common household accident in Taiwan. We propose a wireless and batteryless intelligent CO sensor for improving the safety of operating natural gas water heaters. A micro-hydropower generator supplies power to a CO sensor without battery (COSWOB) (2.5 W at a flow rate of 4.2 L/min), and the power consumption of the COSWOB is only ~13 mW. The COSWOB monitors the CO concentration in ambient conditions around natural gas water heaters and transmits it to an intelligent gateway. When the CO level reaches a dangerous level, the COSWOB alarm sounds loudly. Meanwhile, the intelligent gateway also sends a trigger to activate Wi-Fi alarms and sends notifications to the mobile device through the Internet. Our strategy can warn people indoors and outdoors, thereby reducing CO poisoning accidents. We also believe that our technique not only can be used for home security but also can be used in industrial applications (for example, to monitor leak occurrence in a pipeline). Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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8 pages, 3095 KiB

Open AccessArticle

A Small U-Shaped Bending-Induced Interference Optical Fiber Sensor for the Measurement of Glucose Solutions

by Yu-Lin Fang, Chen-Tung Wang and Chia-Chin Chiang

Sensors 2016, 16(9), 1460; https://doi.org/10.3390/s16091460 - 9 Sep 2016

Cited by 38 | Viewed by 7396

Abstract

The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including [...] Read more.

The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including being difficult to repair and a tendency to be influenced by external forces. We manufactured three types of sensors with different curvature radiuses. Specifically, sensors with three radiuses (1.5 mm, 2.0 mm, and 3.0 mm) were used to measure common water and glucose solutions with concentrations of between 6% and 30% (the interval between concentrations was 4%). The results show that the maximal sensitivity was 0.85 dB/% and that the linearly-dependent coefficient was 0.925. The results further show that not only can the small U-shaped bending-induced interference optical fiber sensor achieve high sensitivity in the measurement of glucose solutions, but that it can also achieve great stability and repeatability. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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16 pages, 5708 KiB

Open AccessArticle

A Study of Dispersion Compensation of Polarization Multiplexing-Based OFDM-OCDMA for Radio-over-Fiber Transmissions

by Chih-Ta Yen and Wen-Bin Chen

Sensors 2016, 16(9), 1440; https://doi.org/10.3390/s16091440 - 7 Sep 2016

Cited by 5 | Viewed by 7296

Abstract

Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectra-amplitude-coding-based optical code-division multiple-access (SAC-OCDMA) system. Thus, the balance detection scheme does not work perfectly to cancel multiple access [...] Read more.

Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectra-amplitude-coding-based optical code-division multiple-access (SAC-OCDMA) system. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference (MAI) and the system performance will be degraded. Orthogonal frequency-division multiplexing (OFDM) is the fastest developing technology in the academic and industrial fields of wireless transmission. In this study, the radio-over-fiber system is realized by integrating OFDM and OCDMA via polarization multiplexing scheme. The electronic dispersion compensation (EDC) equalizer element of OFDM integrated with the dispersion compensation fiber (DCF) is used in the proposed radio-over-fiber (RoF) system, which can efficiently suppress the chromatic dispersion influence in long-haul transmitted distance. A set of length differences for 10 km-long single-mode fiber (SMF) and 4 km-long DCF is to verify the compensation scheme by relative equalizer algorithms and constellation diagrams. In the simulation result, the proposed dispersion mechanism successfully compensates the dispersion from SMF and the system performance with dispersion equalizer is highly improved. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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13 pages, 6624 KiB

Open AccessArticle

The Front-End Readout as an Encoder IC for Magneto-Resistive Linear Scale Sensors

by Trong-Hieu Tran, Paul Chang-Po Chao and Ping-Chieh Chien

Sensors 2016, 16(9), 1416; https://doi.org/10.3390/s16091416 - 2 Sep 2016

Cited by 11 | Viewed by 10998

Abstract

This study proposes a front-end readout circuit as an encoder chip for magneto-resistance (MR) linear scales. A typical MR sensor consists of two major parts: one is its base structure, also called the magnetic scale, which is embedded with multiple grid MR electrodes, [...] Read more.

This study proposes a front-end readout circuit as an encoder chip for magneto-resistance (MR) linear scales. A typical MR sensor consists of two major parts: one is its base structure, also called the magnetic scale, which is embedded with multiple grid MR electrodes, while another is an “MR reader” stage with magnets inside and moving on the rails of the base. As the stage is in motion, the magnetic interaction between the moving stage and the base causes the variation of the magneto-resistances of the grid electrodes. In this study, a front-end readout IC chip is successfully designed and realized to acquire temporally-varying resistances in electrical signals as the stage is in motions. The acquired signals are in fact sinusoids and co-sinusoids, which are further deciphered by the front-end readout circuit via newly-designed programmable gain amplifiers (PGAs) and analog-to-digital converters (ADCs). The PGA is particularly designed to amplify the signals up to full dynamic ranges and up to 1 MHz. A 12-bit successive approximation register (SAR) ADC for analog-to-digital conversion is designed with linearity performance of ±1 in the least significant bit (LSB) over the input range of 0.5–2.5 V from peak to peak. The chip was fabricated by the Taiwan Semiconductor Manufacturing Company (TSMC) 0.35-micron complementary metal oxide semiconductor (CMOS) technology for verification with a chip size of 6.61 mm², while the power consumption is 56 mW from a 5-V power supply. The measured integral non-linearity (INL) is −0.79–0.95 LSB while the differential non-linearity (DNL) is −0.68–0.72 LSB. The effective number of bits (ENOB) of the designed ADC is validated as 10.86 for converting the input analog signal to digital counterparts. Experimental validation was conducted. A digital decoder is orchestrated to decipher the harmonic outputs from the ADC via interpolation to the position of the moving stage. It was found that the displacement measurement error is within ±15 µm for a measuring range of 10 mm. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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15 pages, 6577 KiB

Open AccessArticle

Transportation Modes Classification Using Sensors on Smartphones

by Shih-Hau Fang, Hao-Hsiang Liao, Yu-Xiang Fei, Kai-Hsiang Chen, Jen-Wei Huang, Yu-Ding Lu and Yu Tsao

Sensors 2016, 16(8), 1324; https://doi.org/10.3390/s16081324 - 19 Aug 2016

Cited by 56 | Viewed by 9476

Abstract

This paper investigates the transportation and vehicular modes classification by using big data from smartphone sensors. The three types of sensors used in this paper include the accelerometer, magnetometer, and gyroscope. This study proposes improved features and uses three machine learning algorithms including [...] Read more.

This paper investigates the transportation and vehicular modes classification by using big data from smartphone sensors. The three types of sensors used in this paper include the accelerometer, magnetometer, and gyroscope. This study proposes improved features and uses three machine learning algorithms including decision trees, K-nearest neighbor, and support vector machine to classify the user’s transportation and vehicular modes. In the experiments, we discussed and compared the performance from different perspectives including the accuracy for both modes, the executive time, and the model size. Results show that the proposed features enhance the accuracy, in which the support vector machine provides the best performance in classification accuracy whereas it consumes the largest prediction time. This paper also investigates the vehicle classification mode and compares the results with that of the transportation modes. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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16 pages, 4126 KiB

Open AccessArticle

Generation of Localized Surface Plasmon Resonance Using Hybrid Au–Ag Nanoparticle Arrays as a Sensor of Polychlorinated Biphenyls Detection

by Jing Liu, Haoyuan Cai, Chaoyang Chen, Guangsong Yang and Cheng-Fu Yang

Sensors 2016, 16(8), 1241; https://doi.org/10.3390/s16081241 - 5 Aug 2016

Cited by 8 | Viewed by 6241

Abstract

In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs) were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs). First, their simulating extinction spectra were calculated by discrete dipole [...] Read more.

In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs) were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs). First, their simulating extinction spectra were calculated by discrete dipole approximation (DDA) numerical method by changing the media refractive index. Simulation results showed that as the media refractive index was changed from 1.0 to 1.2, the maximum peak intensity of LSPRs spectra had no apparent change and the wavelength to reveal the maximum peak intensity of LSPRs spectra was shifted lower value. Polystyrene (PS) nanospheres with two differently arranged structures were used as the templates to deposit the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic PNAs by evaporation method. The hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate PNAs were grown on single crystal silicon (c-Si) substrates, and their measured extinction spectra were compared with the calculated results. Finally, the fabricated hexagonal lattices of triangular PNAs were investigated as a sensor of polychlorinated biphenyl solution (PCB-77) by observing the wavelength to reveal the maximum extinction efficiency (λ_max). We show that the adhesion of β-cyclodextrins (SH-β-CD) on the hybrid Au–Ag hexagonal lattice of triangular PNAs could be used to increase the variation of λ_max. We also demonstrate that the adhesion of SH-β-CD increases the sensitivity and detection effect of PCB-77 in hexagonal lattice of triangular PNAs. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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15 pages, 6715 KiB

Open AccessArticle

A Smart Spoofing Face Detector by Display Features Analysis

by ChinLun Lai and ChiuYuan Tai

Sensors 2016, 16(7), 1136; https://doi.org/10.3390/s16071136 - 21 Jul 2016

Cited by 7 | Viewed by 7283

Abstract

In this paper, a smart face liveness detector is proposed to prevent the biometric system from being “deceived” by the video or picture of a valid user that the counterfeiter took with a high definition handheld device (e.g., iPad with retina display). By [...] Read more.

In this paper, a smart face liveness detector is proposed to prevent the biometric system from being “deceived” by the video or picture of a valid user that the counterfeiter took with a high definition handheld device (e.g., iPad with retina display). By analyzing the characteristics of the display platform and using an expert decision-making core, we can effectively detect whether a spoofing action comes from a fake face displayed in the high definition display by verifying the chromaticity regions in the captured face. That is, a live or spoof face can be distinguished precisely by the designed optical image sensor. To sum up, by the proposed method/system, a normal optical image sensor can be upgraded to a powerful version to detect the spoofing actions. The experimental results prove that the proposed detection system can achieve very high detection rate compared to the existing methods and thus be practical to implement directly in the authentication systems. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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10 pages, 2293 KiB

Open AccessArticle

Mechanical Strength and Broadband Transparency Improvement of Glass Wafers via Surface Nanostructures

by Amarendra Kumar, Kunal Kashyap, Max T. Hou and J. Andrew Yeh

Sensors 2016, 16(6), 902; https://doi.org/10.3390/s16060902 - 17 Jun 2016

Viewed by 6163

Abstract

In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for [...] Read more.

In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for surface nanostructure fabrication. Specifically, we improved the bending strength of plain borosilicate glass by 96% using these surface nanostructures on both sides. Besides bending strength improvement, a limited optical transmittance enhancement of 3% was also observed in the visible light wavelength region (400–800 nm). Both strength and transparency were improved by using surface nanostructures of 500 nm depth on both sides of the borosilicate glass without affecting its bulk properties or the glass manufacturing process. Moreover, we observed comparatively smaller fragments during the breaking of the nanostructured glass, which is indicative of strengthening. The range for the nanostructure depth is defined for different applications with which improvements of the strength and transparency of borosilicate glass substrate are obtained. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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15 pages, 6403 KiB

Open AccessArticle

Novel Wearable Device for Blood Leakage Detection during Hemodialysis Using an Array Sensing Patch

by Yi-Chun Du, Bee-Yen Lim, Wei-Siang Ciou and Ming-Jui Wu

Sensors 2016, 16(6), 849; https://doi.org/10.3390/s16060849 - 9 Jun 2016

Cited by 19 | Viewed by 11265

Abstract

Hemodialysis (HD) is a clinical treatment that requires the puncturing of the body surface. However, needle dislodgement can cause a high risk of blood leakage and can be fatal to patients. Previous studies proposed several devices for blood leakage detection using optical or [...] Read more.

Hemodialysis (HD) is a clinical treatment that requires the puncturing of the body surface. However, needle dislodgement can cause a high risk of blood leakage and can be fatal to patients. Previous studies proposed several devices for blood leakage detection using optical or electrical techniques. Nonetheless, these methods used single-point detection and the design was not suitable for multi-bed monitoring. This study proposed a novel wearable device for blood leakage monitoring during HD using an array sensing patch. The array sensing patch combined with a mapping circuit and a wireless module could measure and transmit risk levels. The different risk levels could improve the working process of healthcare workers, and enhance their work efficiency and reduce inconvenience due to false alarms. Experimental results showed that each point of the sensing array could detect up to 0.1 mL of blood leakage and the array sensing patch supports a risk level monitoring system up to 8 h to alert healthcare personnel of pertinent danger to the patients. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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10 pages, 5144 KiB

Open AccessArticle

Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

by Chin-Guo Kuo, Ho Chang and Jian-Hao Wang

Sensors 2016, 16(4), 431; https://doi.org/10.3390/s16040431 - 24 Mar 2016

Cited by 10 | Viewed by 7118

Abstract

In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of [...] Read more.

In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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16 pages, 1830 KiB

Open AccessConcept Paper

Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

by M. Mosleh E. Abu Samak, A. Ashrif A. Bakar, Muhammad Kashif and Mohd Saiful Dzulkifly Zan

Sensors 2016, 16(4), 506; https://doi.org/10.3390/s16040506 - 9 Apr 2016

Cited by 3 | Viewed by 5376

Abstract

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor [...] Read more.

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD)-FDTD method has similar numerical equation properties, which should be calculated as in the previous method. Generally, a small number of arithmetic processes, which result in a shorter simulation time, are desired. The alternating direction implicit technique can be considered a significant step forward for improving the efficiency of unconditionally stable FDTD schemes. This comparative study shows that the local one-dimensional method had minimum relative error ranges of less than 40% for analytical frequencies above 42.85 GHz, and the same accuracy was generated by both methods. Full article

(This article belongs to the Special Issue Applications of Advanced Materials on Microelectronic and Optical Sensors)

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