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Sensor array

N Khalili, X Shen, H E Naguib
The development of flexible pressure sensors with human-like sensing capabilities is an emerging field due to their wide range of applications from human robot interactions to wearable electronics. Piezoresistive sensors respond to externally induced mechanical stimuli through changes in their electrical resistance. The current state-of-the-art piezoresistive sensors are mainly constructed via dispersion of conductive nanofillers in an elastomer matrix making their performance strongly reliable on the degree of dispersion...
August 10, 2018: Soft Matter
Siamak Samavat, Jonathan Lloyd, Laura O'Dea, Wei Zhang, Emily Preedy, Stephen Luzio, Kar Seng Teng
In this study, a uniformly mixed sensing layer of typically immiscible compounds, such as tetrathiafulvalene (TTF) mediator and glucose oxidase (GOx) enzyme, was developed using a simultaneous spray deposition technique ideal for mass production of glucose sensors at low cost while exhibiting enhanced amperometric response. For comparison, the sensors were fabricated via three different methods: conventional drop-cast of TTF and GOx compounds in subsequent layers (DL), spray deposition of the compounds in subsequent layers (SL), and spray mixing of the compounds as one uniform layer (SM)...
July 27, 2018: Biosensors & Bioelectronics
Rikiya Watanabe, Toru Komatsu, Shingo Sakamoto, Yasuteru Urano, Hiroyuki Noji
Micro-reactor arrays enable highly sensitive and quantitative bioassays at a single-molecule level. Accordingly, they are widely used for sensitive "digital" bioassays, e.g., digital PCR and digital ELISA. Despite high integration, individual reactors in digital bioassays are filled with a uniform reaction solution, thus limiting the ability to simultaneously conduct multiple bioassays under different conditions using integrated reactors in parallel, resulting in the loss of potential throughput. We developed micro-reactor arrays with a concentration gradient of target molecules, in which individual reactors sealed with a lipid-bilayer membrane contained a precise amount of target molecules...
August 9, 2018: Lab on a Chip
Xiao Lian, Bing Yan
Logic circuit device and molecule computer are idealized binary tools to implement manifold signals transformation and operation, which is a basic component of integrated circuits and widely used in computer, CNC (Computerized Numerical Control) and communication fields. By combining the advantages of the synthetic feasibility and enantio-selective luminescent recognition, a logic device based on the lanthanide functional membrane has been constructed, for effective recognize enantiomer and judge the enantiomer excess of chair drug mixture...
August 9, 2018: ACS Applied Materials & Interfaces
Adrien Nougarède, Chloé Tesnière, Jarkko Ylanko, Ruth Rimokh, Germain Gillet, David W Andrews
In response to a variety of insults the unfolded protein response (UPR) is a major cell program quickly engaged to promote either cell survival or if stress levels cannot be relieved, apoptosis. UPR relies on three major pathways, named from the endoplasmic reticulum (ER) resident proteins IRE1α, PERK, and ATF6 that mediate response. Current tools to measure the activation of these ER stress response pathways in mammalian cells are cumbersome and not compatible with high-throughput imaging. In this study, we present IRE1α and PERK sensors with improved sensitivity, based on the canonical events of xbp1 splicing and ATF4 translation at ORF3...
August 8, 2018: Assay and Drug Development Technologies
Larisa Lvova, Irina Yaroshenko, Dmitry Kirsanov, Corrado Di Natale, Roberto Paolesse, Andrey Legin
The potentiometric electronic tongue system has been tested as a potential analytical tool for brand uniformity control of monoculture Apulian red wines (Primitivo and Negroamaro). The sensor array was composed of eight porphyrin coatings obtained by electrochemical polymerization process and was employed for both wines discrimination and quantitative detection of wine defect compounds: "off-odour" 3-(methylthio)-propanol; isoamyl alcohol fusel oil; benzaldehyde (marker of the yeast activity) and acetic acid (marker of vinegar formation)...
August 7, 2018: Sensors
Zhenzhen Fan, Lifang Fan, Shaomin Shuang, Chuan Dong
A facile and sensitive photoelectrochemical (PEC) sensing platform based on zinc phthalocyanine (ZnPc) sensitized TiO2 nanorodarrays (NRAs) was successfully fabricated for detection of bisphenol A (BPA). The vertically aligned TiO2 NRAs with one-dimensional (1D) nanostructure was synthesized in-situ on fluorine-doped tin oxide-coated glass (FTO) substrate by simple one-step hydrothermal method, and then the TiO2 NRAs/FTO surface was covered with ZnPc. 1D nanostructure of TiO2 NRAs could provide not only more spaces for the load of ZnPc, but direct pathways to reduce the recombination of electron-hole pairs, improving the photocatalytic efficiency...
November 1, 2018: Talanta
Saewon Kang, Seungse Cho, Ravi Shanker, Hochan Lee, Jonghwa Park, Doo-Seung Um, Youngoh Lee, Hyunhyub Ko
We demonstrate ultrathin, transparent, and conductive hybrid nanomembranes (NMs) with nanoscale thickness, consisting of an orthogonal silver nanowire array embedded in a polymer matrix. Hybrid NMs significantly enhance the electrical and mechanical properties of ultrathin polymer NMs, which can be intimately attached to human skin. As a proof of concept, we present a skin-attachable NM loudspeaker, which exhibits a significant enhancement in thermoacoustic capabilities without any significant heat loss from the substrate...
August 2018: Science Advances
Van-Viet Nguyen, Hyohyun Nam, Young Joe Choe, Bok-Hyung Lee, Jung-Dong Park
We present an X-band bi-directional transmit/receive module (TRM) for a phased array system utilized in radar-based sensor systems. The proposed module, comprising a 6-bit phase shifter, a 6-bit digital step attenuator, and bi-directional gain amplifiers, is fabricated using 65-nm CMOS technology. By constructing passive networks in the phase-shifter and the variable attenuator, the implemented TRM provides amplitude and phase control with 360° phase coverage and 5.625° as the minimum step size while the attenuation range varies from 0 to 31...
August 6, 2018: Sensors
Yong Wang, Yixin Yang, Shiduo Yu
This letter proposes a method of designing unidirectional acoustic probes with flexible directivity patterns using two acoustic particle velocity sensors. The closed-form weighting vector of this two-sensor array is accurately derived by finding the minimum mean square error approximation to a desired directivity pattern that is expressed in a general form. Different unidirectional acoustic probes can be obtained by properly selecting the desired directivity pattern, and the previously proposed particle velocity gradient-based design approach can be thought of as a special case of the proposed method...
July 2018: Journal of the Acoustical Society of America
Shima H Abadi, Kevin J Haworth, Karla P Mercado-Shekhar, David R Dowling
Beamforming includes a variety of spatial filtering techniques that may be used for determining sound source locations from near-field sensor array recordings. For this scenario, beamforming resolution depends on the acoustic frequency, array geometry, and target location. Random scattering in the medium between the source and the array may degrade beamforming resolution with higher frequencies being more susceptible to degradation. The performance of frequency-sum (FS) beamforming for reducing such sensitivity to mild scattering while increasing resolution is reported here...
July 2018: Journal of the Acoustical Society of America
Gongping Huang, Jingdong Chen, Jacob Benesty
This letter deals with the problem of differential beamforming with microphone arrays of arbitrary planar geometry. By approximating the beampattern with the Jacobi-Anger expansion, it develops an algorithm that can form any specified frequency-invariant beampattern with a microphone array of any planar geometry as long as the sensors' coordinates are given and the spacing between neighboring sensors is smaller than the smallest wavelength. This method is rather general and it can be used to design differential beamformers with linear, circular, and concentric circular differential microphone arrays as well as differential arrays of arbitrary planar geometry where sensors are placed in any specified positions...
July 2018: Journal of the Acoustical Society of America
Liang Shang, Chuanjun Liu, Bin Chen, Kenshi Hayashi
Detection of plant volatile organic compounds (VOCs) enables monitoring of pests and diseases in agriculture. We previously revealed that a localized surface plasmon resonance (LSPR) sensor coated with a molecularly imprinted sol-gel (MISG) can be used for cis-jasmone vapor detection. Although the selectivity of the LSPR sensor was enhanced by the MISG coating, its sensitivity was decreased. Here, gold nanoparticles (AuNPs) were doped in the MISG to enhance the sensitivity of the LSPR sensor through hot spot generation...
August 3, 2018: ACS Sensors
Shipu Xu, Yang Xu, Huaping Zhao, Rui Xu, Yong Lei
It is a widely used strategy to enhance a gas sensor sensitivity by improving its surface area, but this process, including bonding the sensing block into a device substrate, needs complex manipulations. This work shows a concept of adsorption active site, by which an SnO2 layer (6.85 nm thin) is directly coated on a triangle array substrate to be of an ensemble of triangular convex adsorption active sites (TCAASs). The resultant SnO2 gas sensors, with TCAAS periods ranging from 289 to 1154 nm, exhibit an adsorption-active-site-dependent sensitivity and present a low detection limit of around 6 ppm ethanol gas at room temperature...
August 3, 2018: ACS Applied Materials & Interfaces
Paolo Di Barba, Teodor Gotszalk, Wojciech Majstrzyk, Maria Evelina Mognaschi, Karolina Orłowska, Sławomir Wiak, Andrzej Sierakowski
In this paper we present the numerical and experimental results of a design optimization of electromagnetic cantilevers. In particular, a cost-effective technique of evolutionary computing enabling the simultaneous minimization of multiple criteria is applied. A set of optimal solutions are subsequently fabricated and measured. The designed cantilevers are fabricated in arrays, which makes the comparison and measurements of the sensor properties reliable. The microfabrication process, based on the silicon on insulator (SOI) technology, is proposed in order to minimize parasitic phenomena and enable efficient electromagnetic actuation...
August 2, 2018: Sensors
Lei Zhang, Shiwei Ren, Xiangnan Li, Guishan Ren, Xiaohua Wang
In this paper, a generalized L-shaped nested array based on the fourth-order difference co-array is proposed for two-dimensional (2D) directions' estimation. The new structure framework makes full use of the physical sensor locations to form a virtual uniform rectangular array (URA) as large as possible. As it utilizes the fourth-order difference instead of the traditional second-order difference result, this structure framework can acquire a much higher degree-of-freedom (DOF) than the existing 2D sparse arrays...
August 1, 2018: Sensors
Benjamin J Brownlee, Meisam Bahari, John N Harb, Jonathan C Claussen, Brian D Iverson
Free-standing, vertically aligned carbon nanotubes (VACNTs) were patterned into 16 µm diameter microchannel arrays for flow-through electrochemical glucose sensing. Non-enzymatic sensing of glucose was achieved by the chemical reaction of glucose with methyl viologen (MV) at an elevated temperature and pH (0.1 M NaOH), followed by the electrochemical reaction of reduced-MV with the VACNT surface. The MV sensor required no functionalization (including no metal) and was able to produce on average 3.4 electrons per glucose molecule...
August 1, 2018: ACS Applied Materials & Interfaces
Désirée L Röhlen, Johanna Pilas, Markus Dahmen, Michael Keusgen, Thorsten Selmer, Michael J Schöning
Monitoring of organic acids (OA) and volatile fatty acids (VFA) is crucial for the control of anaerobic digestion. In case of unstable process conditions, an accumulation of these intermediates occurs. In the present work, two different enzyme-based biosensor arrays are combined and presented for facile electrochemical determination of several process-relevant analytes. Each biosensor utilizes a platinum sensor chip (14 × 14 mm2 ) with five individual working electrodes. The OA biosensor enables simultaneous measurement of ethanol, formate, d- and l-lactate, based on a bi-enzymatic detection principle...
2018: Frontiers in Chemistry
Jubo Hao, Jin Li, Yiming Pi
Due to the non-contact detection ability of radar and the harmlessness of terahertz waves to the human body, three-dimensional (3D) imaging using terahertz synthetic aperture radar (SAR) is an efficient method of security detection in public areas. To achieve high-resolution and all aspect imaging, circular trajectory movement of radar and linear sensor array along the height direction were used in this study. However, the short wavelength of terahertz waves makes it practically impossible for the hardware to satisfy the half-wavelength spacing condition to avoid grating lobes...
July 31, 2018: Sensors
Hao Lin, Zhong-Xiu Man, Wen-Cui Kang, Bin-Bin Guan, Quan-Sheng Chen, Zhao-Li Xue
A novel colorimetric sensor array based on boron-dipyrromethene (BODIPY) dyes was developed to monitor the volatile organic compounds (VOCs) of rice at different storage times. The VOCs of rice at different storage times were analyzed through GC-MS combined with multivariate analysis, and the compound 18-crown-6 was found significantly changed during rice aging process. Aimed at 18-crown-6 with particular macrocyclic structure, a series of BODIPYs were targeted synthesized for the selection of sensitive chemically responsive dyes...
December 1, 2018: Food Chemistry
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