Low cost sponge based piezocapacitive sensors using a single step leavening agent mediated autolysis process

A single step, low cost, large area and shape scalable method of obtaining elastomer sponge is achieved through leavening agent autolysis with exceptional sensitivity tunability for real time sensing applications.

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Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020190250 ◽

2020 ◽

Vol 90 (3) ◽

pp. 30502

Author(s):

Alessandro Fantoni ◽

João Costa ◽

Paulo Lourenço ◽

Manuela Vieira

Keyword(s):

Amorphous Silicon ◽

High Throughput Screening ◽

Simulation Analysis ◽

Low Cost ◽

Deposition Process ◽

Large Area ◽

Sidewall Roughness ◽

Sensing Applications ◽

Fabrication Defects ◽

The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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Humidity sensor based on Gallium Nitride for real time monitoring applications

Scientific Reports ◽

10.1038/s41598-021-89956-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chaudhry Muhammad Furqan ◽

Muhammad Umair Khan ◽

Muhammad Awais ◽

Fulong Jiang ◽

Jinho Bae ◽

...

Keyword(s):

Gallium Nitride ◽

Real Time ◽

Humidity Sensor ◽

Low Cost ◽

Fast Response ◽

Current Response ◽

High Electron ◽

Real Time Monitoring ◽

Sensing Applications ◽

Monitoring Applications

AbstractGallium Nitride (GaN) remarkably shows high electron mobility, wide energy band gap, biocompatibility, and chemical stability. Wurtzite structure makes topmost Gallium atoms electropositive, hence high ligand binding ability especially to anions, making it usable as humidity sensor due to water self-ionization phenomenon. In this work, thin-film GaN based humidity sensor is fabricated through pulse modulated DC magnetron sputtering. Interdigitated electrodes (IDEs) with 100 μm width and spacing were inkjet printed on top of GaN sensing layer to further enhance sensor sensitivity. Impedance, capacitance, and current response were recorded for humidity and bio-sensing applications. The sensor shows approximate linear impedance response between 0 and 100% humidity range, the sensitivity of 8.53 nF/RH% and 79 kΩ/RH% for capacitance and impedance, and fast response (Tres) and recovery (Trec) time of 3.5 s and 9 s, respectively. The sensor shows little hysteresis of < 3.53% with stable and wide variations for accurate measurements. Especially, it demonstrates temperature invariance for thermal stability. Experimental results demonstrate fabricated sensor effectively evaluates plant transpiration cycle through water level monitoring by direct attachment onto leaves without causing any damage as well as freshness level of meat loaf. These properties of the proposed sensor make it a suitable candidate for future electronics providing a low-cost platform for real time monitoring applications.

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REAL-TIME AND POST-PROCESSED GEOREFERENCING FOR HYPERPSPECTRAL DRONE REMOTE SENSING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-789-2018 ◽

2018 ◽

Vol XLII-2 ◽

pp. 789-795 ◽

Cited By ~ 3

Author(s):

R. A. Oliveira ◽

E. Khoramshahi ◽

J. Suomalainen ◽

T. Hakala ◽

N. Viljanen ◽

...

Keyword(s):

Remote Sensing ◽

Real Time ◽

Precision Agriculture ◽

Low Cost ◽

Remote Sensing Data ◽

Target Object ◽

Post Processing ◽

The Real ◽

Sensing Applications ◽

Remote Sensing Applications

The use of drones and photogrammetric technologies are increasing rapidly in different applications. Currently, drone processing workflow is in most cases based on sequential image acquisition and post-processing, but there are great interests towards real-time solutions. Fast and reliable real-time drone data processing can benefit, for instance, environmental monitoring tasks in precision agriculture and in forest. Recent developments in miniaturized and low-cost inertial measurement systems and GNSS sensors, and Real-time kinematic (RTK) position data are offering new perspectives for the comprehensive remote sensing applications. The combination of these sensors and light-weight and low-cost multi- or hyperspectral frame sensors in drones provides the opportunity of creating near real-time or real-time remote sensing data of target object. We have developed a system with direct georeferencing onboard drone to be used combined with hyperspectral frame cameras in real-time remote sensing applications. The objective of this study is to evaluate the real-time georeferencing comparing with post-processing solutions. Experimental data sets were captured in agricultural and forested test sites using the system. The accuracy of onboard georeferencing data were better than 0.5&thinsp;m. The results showed that the real-time remote sensing is promising and feasible in both test sites.

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Low-Cost, Disposable, Flexible and Highly Reproducible Screen Printed SERS Substrates for the Detection of Various Chemicals

Scientific Reports ◽

10.1038/srep10208 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 74

Author(s):

Wei Wu ◽

Li Liu ◽

Zhigao Dai ◽

Juhua Liu ◽

Shuanglei Yang ◽

...

Keyword(s):

Screen Printing ◽

Large Scale ◽

Low Cost ◽

Large Area ◽

Sers Substrates ◽

Sensing Applications ◽

Relative Standard ◽

Sers Detection ◽

On Line ◽

Liquid Milk

Abstract Ideal SERS substrates for sensing applications should exhibit strong signal enhancement, generate a reproducible and uniform response and should be able to fabricate in large-scale and low-cost. Herein, we demonstrate low-cost, highly sensitive, disposable and reproducible SERS substrates by means of screen printing Ag nanoparticles (NPs) on a plastic PET (Polyethylene terephthalate) substrates. While there are many complex methods for the fabrication of SERS substrates, screen printing is suitable for large-area fabrication and overcomes the uneven radial distribution. Using as-printed Ag substrates as the SERS platform, detection of various commonly known chemicals have been done. The SERS detection limit of Rhodamine 6G (R6G) is higher than the concentration of 1 × 10−10 M. The relative standard deviation (RSD) value for 784 points on the detection of R6G and Malachite green (MG) is less than 20% revealing a homogeneous SERS distribution and high reproducibility. Moreover, melamine (MA) is detected in fresh liquid-milk without additional pretreatment, which may accelerate the application of rapid on-line detection of MA in liquid milk. Our screen printing method highlights the use of large-scale printing strategies for the fabrication of well-defined functional nanostructures with applications well beyond the field of SERS sensing.

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Plasmonic nanoparticle enhanced and extended performance of Light-sensitive nanocrystal skins

MRS Proceedings ◽

10.1557/opl.2013.547 ◽

2013 ◽

Vol 1509 ◽

Author(s):

Shahab Akhavan ◽

Kivanc Gungor ◽

Hilmi Volkan Demir

Keyword(s):

Optical Absorption ◽

Low Cost ◽

Great Promise ◽

Silver Nanostructures ◽

Ambient Conditions ◽

Large Area ◽

Plasmonic Nanoparticle ◽

Noise Current ◽

External Bias ◽

Sensing Applications

ABSTRACTWe report on light-sensitive nanocrystal skin (LS-NS) platforms composed of monolayer visible nanocrystals (NCs) on top of bilayers of polyelectrolyte polymers. These LS-NS devices are operated on the principle of photogenerated potential buildup, unlike common photodetectors that operate on the basis of charge collection. The resulting devices are as highly sensitive as common photosensors, despite utilizing a monolayer of NCs and requiring no applied external bias. In this device architecture, using only a single NC monolayer also allows to reduce noise current generation. This LS-NS platform is highly stable under ambient conditions with fully sealed NC monolayer, promising for low-cost large-area UV/visible sensing applications. However, such visible NC based LS-NS devices exhibit limited performance in the long wavelength range due to the low optical absorption of these NCs (e.g., CdTe NCs) in this spectral range. Here, to enhance the device sensitivity, incorporating silver nanoparticles into LS-NS is proposed and demonstrated. For that, the optical absorption of CdTe monolayer NCs in the LS-NS devices is increased using the embedded silver nanostructures. With plasmon coupling, we observe a 2.6-fold enhancement factor in the photosensitivity around the localized surface plasmonic resonance peak of the nanostructures. Higher sensitivity improvement is also obtained at longer wavelengths. To predict the enhancement in the sensitivity of the LS-NS, numerical simulations are performed and the simulation results are found to agree well with the experimental data. Plasmonically enhanced LS-NS hold great promise for large-area photosensing applications extending from UV to IR including windows and facades of smart buildings.

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Spray-combustion synthesis: Efficient solution route to high-performance oxide transistors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1501548112 ◽

2015 ◽

Vol 112 (11) ◽

pp. 3217-3222 ◽

Cited By ~ 119

Author(s):

Xinge Yu ◽

Jeremy Smith ◽

Nanjia Zhou ◽

Li Zeng ◽

Peijun Guo ◽

...

Keyword(s):

Combustion Synthesis ◽

High Performance ◽

Low Cost ◽

Sol Gel ◽

Amorphous State ◽

Single Step ◽

Spray Combustion ◽

Indium Gallium Zinc Oxide ◽

Large Area ◽

Solution Processed

Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations.

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Long- and Short-Range Ordered Gold Nanoholes as Large-Area Optical Transducers in Sensing Applications

Chemosensors ◽

10.3390/chemosensors7010013 ◽

2019 ◽

Vol 7 (1) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Maura Cesaria ◽

Adriano Colombelli ◽

Daniela Lospinoso ◽

Antonietta Taurino ◽

Enrico Melissano ◽

...

Keyword(s):

Self Assembly ◽

Short Range ◽

Low Cost ◽

Hexagonal Lattice ◽

Solid Substrate ◽

Attractive Alternative ◽

Large Area ◽

Glass Substrates ◽

Self Assembling ◽

Sensing Applications

Unconventional lithography (such as nanosphere lithography (NSL) and colloidal lithography (CL)) is an attractive alternative to sequential and very expensive conventional lithography for the low-cost fabrication of large-area nano-optical devices. Among these, nanohole (NH) arrays are widely studied in nanoplasmonics as transducers for sensing applications. In this work, both NSL and CL are implemented to fabricate two-dimensional distributions of gold NHs. In the case of NSL, highly ordered arrays of gold NHs distributed in a hexagonal lattice onto glass substrates were fabricated by a simple and reproducible approach based on the self-assembling of close-packed 500 nm diameter polystyrene particles at an air/water interface. After the transfer onto a solid substrate, the colloidal masks were processed to reduce the colloidal size in a controllable way. In parallel, CL was implemented with short-range ordered gold NH arrays onto glass substrates that were fabricated by electrostatically-driven self-assembly of negatively charged colloids onto a polydiallyldimethylammonium (PDDA) monolayer. These distributions were optimized as a function of the colloidal adsorption time. For both approaches, controllable and reproducible procedures are presented and discussed. The optical responses of the NH structures are related to the short-range ordering level, and their good performances as refractive index transducers are demonstrated.

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