scholarly journals Thin Film Protected Flexible Nanoparticle Strain Sensors: Experiments and Modeling

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2584 ◽  
Author(s):  
Evangelos Aslanidis ◽  
Evangelos Skotadis ◽  
Evangelos Moutoulas ◽  
Dimitris Tsoukalas
Keyword(s):  
Protective Coatings ◽  
Flexible Substrate ◽  
Mechanical Strain ◽  
Atomic Layer ◽  
Strain Sensors ◽  
Solvent Free ◽  
Alumina Layer ◽  
Sensor Resistance ◽  
Proposed Model ◽  
Effective Manner

In this work, the working performance of Platinum (Pt), solvent-free nanoparticle (NP)-based strain sensors made on a flexible substrate has been studied. First, a new model has been developed in order to explain sensor behaviour under strain in a more effective manner than what has been previously reported. The proposed model also highlights the difference between sensors based on solvent-free and solvent-based NPs. As a second step, the ability of atomic layer deposition (ALD) developed Al2O3 (alumina) thin films to act as protective coatings against humidity while in adverse conditions (i.e., variations in relative humidity and repeated mechanical stress) has been evaluated. Two different alumina thicknesses (5 and 11 nm) have been tested and their effect on protection against humidity is studied by monitoring sensor resistance. Even in the case of adverse working conditions and for increased mechanical strain (up to 1.2%), it is found that an alumina layer of 11 nm provides sufficient sensor protection, while the proposed model remains valid. This certifies the appropriateness of the proposed strain-sensing technology for demanding applications, such as e-skin and pressure or flow sensing, as well as the possibility of developing a comprehensive computational tool for NP-based devices.

scholarly journals Reliability-Aware SPICE Compatible Compact Modeling of IGZO Inverters on a Flexible Substrate

2021 ◽  
Vol 11 (11) ◽  
pp. 4838
Author(s):  
Je-Hyuk Kim ◽  
Youngjin Seo ◽  
Jun Tae Jang ◽  
Shinyoung Park ◽  
Dongyeon Kang ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Circuit Simulation ◽  
Flexible Substrate ◽  
Atomic Layer ◽  
Operating Conditions ◽  
Gate Insulator ◽  
Compact Modeling ◽  
Indium Gallium Zinc Oxide ◽  
Electrical Stress ◽  
Bending Radius

Accurate circuit simulation reflecting physical and electrical stress is of importance in indium gallium zinc oxide (IGZO)-based flexible electronics. In particular, appropriate modeling of threshold voltage (VT) changes in different bias and bending conditions is required for reliability-aware simulation in both device and circuit levels. Here, we present SPICE compatible compact modeling of IGZO transistors and inverters having an atomic layer deposition (ALD) Al2O3 gate insulator on a polyethylene terephthalate (PET) substrate. Specifically, the modeling was performed to predict the behavior of the circuit using stretched exponential function (SEF) in a bending radius of 10 mm and operating voltages ranging between 4 and 8 V. The simulation results of the IGZO circuits matched well with the measured values in various operating conditions. It is expected that the proposed method can be applied to process improvement or circuit design by predicting the direct current (DC) and alternating current (AC) responses of flexible IGZO circuits.

scholarly journals Plant Disease Identification Using Shallow Convolutional Neural Network

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2388
Author(s):  
Sk Mahmudul Hassan ◽  
Michal Jasinski ◽  
Zbigniew Leonowicz ◽  
Elzbieta Jasinska ◽  
Arnab Kumar Maji
Keyword(s):  
Deep Learning ◽  
Late Blight ◽  
Early Blight ◽  
Gray Leaf Spot ◽  
Plant Diseases ◽  
Automated Identification ◽  
Average Accuracy ◽  
Proposed Model ◽  
Effective Manner ◽  
Tomato Diseases

Various plant diseases are major threats to agriculture. For timely control of different plant diseases in effective manner, automated identification of diseases are highly beneficial. So far, different techniques have been used to identify the diseases in plants. Deep learning is among the most widely used techniques in recent times due to its impressive results. In this work, we have proposed two methods namely shallow VGG with RF and shallow VGG with Xgboost to identify the diseases. The proposed model is compared with other hand-crafted and deep learning-based approaches. The experiments are carried on three different plants namely corn, potato, and tomato. The considered diseases in corns are Blight, Common rust, and Gray leaf spot, diseases in potatoes are early blight and late blight, and tomato diseases are bacterial spot, early blight, and late blight. The result shows that our implemented shallow VGG with Xgboost model outperforms different deep learning models in terms of accuracy, precision, recall, f1-score, and specificity. Shallow Visual Geometric Group (VGG) with Xgboost gives the highest accuracy rate of 94.47% in corn, 98.74% in potato, and 93.91% in the tomato dataset. The models are also tested with field images of potato, corn, and tomato. Even in field image the average accuracy obtained using shallow VGG with Xgboost are 94.22%, 97.36%, and 93.14%, respectively.

Highly Sensitive Solvent-free Silver Nanoparticle Strain Sensors with Tunable Sensitivity Created Using an Aerodynamically Focused Nanoparticle Printer

2019 ◽  
Vol 11 (29) ◽  
pp. 26421-26432 ◽  
Author(s):  
Gil-Yong Lee ◽  
Min-Soo Kim ◽  
Soo-Hong Min ◽  
Hyung-Soo Kim ◽  
Ho-Jin Kim ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
Strain Sensors ◽  
Solvent Free ◽  
Highly Sensitive

A Creep-Fatigue-Oxidation Microcrack Propagation Model for Thermomechanical Fatigue

1992 ◽  
Vol 114 (3) ◽  
pp. 282-288 ◽  
Author(s):  
M. P. Miller ◽  
D. L. McDowell ◽  
R. L. T. Oehmke
Keyword(s):  
Mechanical Strain ◽  
Thermomechanical Fatigue ◽  
Propagation Model ◽  
Additional Time ◽  
Basic Model ◽  
Proposed Model ◽  
Microcrack Propagation ◽  
Creep Fatigue ◽  
Phase Out ◽  
Model Features

A high temperature fatigue (HTF) life prediction model is developed based on the concept of microcrack propagation. The model is used to correlate isothermal HTF and thermomechanical fatigue (TMF) life for the Ni-base superalloy MAR-M247. The mechanical strain versus temperature relationships for the TMF tests include in-phase, out-of-phase, and a counter-clockwise diamond history. The proposed model explicitly accounts for damage from all three HTF damage mechanisms: fatigue, oxidation, and creep. The fatigue and oxidation components are correlated using the ΔJ parameter with an additional time dependence included in the oxidation term. The creep component is correlated using a stress power release rate-type parameter, Cˆ. In this paper, we focus on application of a model to HTF and TMF of Ni-base superalloys. However, the basic model features may well apply to other classes of metallic materials.

Microdevice for Delivering Homogeneous Equi-Biaxial Strain to Live Cells Without the Use of Platen Structures

2013 ◽  
Author(s):  
Qian Wang ◽  
Yi Zhao
Keyword(s):  
Cultured Cells ◽  
Flexible Substrate ◽  
Mechanical Strain ◽  
Live Cells ◽  
Biaxial Strain ◽  
Thin Membrane ◽  
Strain Homogeneity ◽  
Homogeneous Strain

Live cells from most of the membranous tissues such as alveoli are subjected to equi-biaxial strain originated from their extracellular environments. To understand the role of equi-biaxial strain in live cells, a number of engineered methods have been developed for applying such mechanical strain to in vitro cultured cells. Among these methods, deforming a flexible substrate on a circular platen has been widely used [1], and has been miniaturized into millimeter scale for parallel stretching assay (Figure 1a). Nonetheless, the strain homogeneity becomes increasingly challenging at smaller scale, since it requires an ultra-thin membrane, an indentation platen with well controlled dimension, and the highly precise alignment. This obviously increases the fabrication and operation complexities. Devices that deliver homogeneous strain with minimal fabrication and assembling complexities are needed.

Two-Sided Topological Architecture on a Monolithic Flexible Substrate for Ultrasensitive Strain Sensors

2019 ◽  
Vol 11 (46) ◽  
pp. 43543-43552 ◽  
Author(s):  
He Yu ◽  
Yunlu Lian ◽  
Teng Sun ◽  
Xiaonan Yang ◽  
Yang Wang ◽  
...  
Keyword(s):  
Flexible Substrate ◽  
Strain Sensors

scholarly journals Atomic Layer Deposited Protective Layers

2016 ◽  
Vol 879 ◽  
pp. 1086-1092
Author(s):  
Markku Leskela ◽  
Emma Salmi ◽  
Mikko Ritala
Keyword(s):  
Protective Coatings ◽  
Atomic Layer ◽  
Energy Technology ◽  
Li Ion Batteries ◽  
Protective Layers ◽  
Layer Deposition ◽  
Li Ion ◽  
Moisture Barriers ◽  
The Stability ◽  
Protection Of Metals

This paper reviews the use of Atomic Layer Deposition (ALD) in protective coatings. Because of the growth principle ALD allows the deposition of dense conformal films on substrates of different size and shape. Recently, ALD has received increasingly interest in deposition of protective coatings. In protective coatings oxides are the most common materials and especially Al, Ti, and Ta oxides have been applied. The use of nanolaminates enables improving the protection properties. Since ALD films are pinhole-free and often thin they are used to protect against moisture, radiation, out-gassing but not often against corrosion of metals. Very good moisture barriers are obtained with thin ALD oxide layers on polymers and cardboard. This property is also very attractive in encapsulation of OLEDs. In studies of energy technology materials protection of electrodes in Li-ion batteries, fuel cells and supercapacitors by ALD has been reported and significant improvement in the stability has been achieved. Yet another area is protection of silver jewelry from tarnishing by a thin oxide layer. In traditional corrosion protection of metals ALD films have proven to be useful in tailoring of interfaces and sealing of defects in coatings made by other techniques.

The Business of Fast ALD Equipment for Depositing Alumina Passivation Layers on Crystalline Silicon Solar Cells.

2011 ◽  
Vol 1353 ◽  
Author(s):  
Ad Vermeer ◽  
Roger Gortzen ◽  
P. Poodt ◽  
F. Roozeboom
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Throughput ◽  
Crystalline Silicon ◽  
Atomic Layer ◽  
Silicon Solar Cells ◽  
Alumina Layer ◽  
Solar Cell Efficiency ◽  
Crystalline Silicon Solar Cells ◽  
Cell Efficiency

ABSTRACTAtomic Layer Deposition (ALD) is a gas phase deposition technique for depositing very high quality thin films with an unsurpassed conformality. The main drawback of ALD however is the very low deposition rate (~ 1 nm/min). Recently, record deposition rates for alumina of up to 1 nm/s were reached using spatial ALD, while maintaining the typical assets regarding film quality as obtained by conventional, slow ALD [1]. This allows for ALD at high throughput numbers.One interesting application is passivation of crystalline silicon solar cells. Applying a thin alumina layer is reported to increase solar cell efficiency and enables the use of thinner wafers, thus reducing the main cost factor [2]. In this paper we report on the latest progress made by SoLayTec that delivered a working prototype of a system realizing full area single sided deposition of alumina on 156 x 156 mm2, mono- and multi crystalline silicon wafers for solar cell applications. The alumina layers showed excellent passivation. Based on this concept, a high-throughput ALD deposition tool is being developed targeting throughput numbers of up to 3000 wafers/hr. Finally, we report on the process of commercializing this technology.

scholarly journals Thermal and plasma enhanced atomic layer deposition of ultrathin TiO2 on silicon from amide and alkoxide precursors: growth chemistry and photoelectrochemical performance.

2021 ◽  
Author(s):  
Shane O'Donnell ◽  
Feljin Jose ◽  
Kyle Shiel ◽  
Matthew Snelgrove ◽  
Caitlin McFeely ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Protective Coatings ◽  
Low Cost ◽  
Atomic Layer ◽  
Photoelectrochemical Cell ◽  
Photoelectrochemical Performance ◽  
Tio2 Thin Films ◽  
Carbon Incorporation ◽  
Layer Deposition

Abstract Due to its low cost and suitable band gap, silicon has been studied as a photoanode material for some time. However, as a result of poor stability during the oxygen evolution reaction (OER), Si still remains unsuitable for any extended use. Ultra-thin titanium dioxide (TiO2) films have been used as protective coatings and are shown to enhance Si photoanode lifetime with added solar to hydrogen (STH) performance improvements through distancing the oxidation reaction away from the Si photoanode surface and improved charge transport through the anode. This study details the nucleation, growth chemistry, and performance of TiO2 thin films prepared via thermal and plasma enhanced atomic layer deposition (ALD) using both titanium isopropoxide (TTIP) and Tetrakis(dimethylamido)titanium (TDMAT) as the precursor material. The effect of post ALD treatments of plasma and air annealing was also studied. Films were investigated using photoelectrochemical cell testing to evaluate photoelectrochemical performance, and in-vacuum cycle-by-cycle x-ray photoelectron spectroscopy (XPS) was used as the primary characterisation technique to study nucleation mechanisms and film properties contributing to improvements in cell performance. TiO2 grown by plasma enhanced ALD results in cleaner films with reduced carbon incorporation. However, despite increased carbon incorporation, thermally grown films showed improved photocurrent as a result of oxygen vacancies in these films. Post deposition annealing in a H2 ambient is shown to further improve photocurrent in all cases, while annealing in atmosphere leads to uniform film chemistry and enhanced photocurrent stability in all cases.

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