scholarly journals Defect Filling Method of Sensor Encapsulation Based on Micro-Nano Composite Structure with Parylene Coating

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1107
Author(s):  
Jialin Yao ◽  
Wenjiang Qiang ◽  
Xingqi Guo ◽  
Hanshui Fan ◽  
Yushuang Zheng ◽  
...  
Keyword(s):  
Composite Structure ◽  
Diffusion Mechanism ◽  
Atomic Layer ◽  
Organic Polymer ◽  
Water Molecules ◽  
Al2o3 Nanoparticles ◽  
Sensors And Actuators ◽  
Nano Composite ◽  
Filling Method ◽  
Defect Filling

The demand for waterproofing of polymer (parylene) coating encapsulation has increased in a wide variety of applications, especially in the waterproof protection of electronic devices. However, parylene coatings often produce pinholes and cracks, which will reduce the waterproof effect as a protective barrier. This characteristic has a more significant influence on sensors and actuators with movable parts. Thus, a defect filling method of micro-nano composite structure is proposed to improve the waterproof ability of parylene coatings. The defect filling method is composed of a nano layer of Al2O3 molecules and a micro layer of parylene polymer. Based on the diffusion mechanism of water molecules in the polymer membrane, defects on the surface of polymer encapsulation will be filled and decomposed into smaller areas by Al2O3 nanoparticles to delay or hinder the penetration of water molecules. Accordingly, the dense Al2O3 nanoparticles are utilized to fill and repair the surface of the organic polymer by low-rate atomic layer deposition. This paper takes the pressure sensor as an example to carry out the corresponding research. Experimental results show that the proposed method is very effective and the encapsulated sensors work properly in a saline solution after a period of time equivalent to 153.9 days in body temperature, maintaining their accuracy and precision of 2 mmHg. Moreover, the sensors could improve accuracy by about 43% after the proposed encapsulation. Therefore, the water molecule anti-permeability encapsulation would have broad application prospects in micro/nano-device protection.

A first-principles study of the atomic layer deposition of ZnO on carboxyl functionalized carbon nanotubes: the role of water molecules

2021 ◽  
Vol 23 (5) ◽  
pp. 3467-3478
Author(s):  
J. I. Paez-Ornelas ◽  
H. N. Fernández-Escamilla ◽  
H. A. Borbón-Nuñez ◽  
H. Tiznado ◽  
Noboru Takeuchi ◽  
...  
Keyword(s):  
First Principles ◽  
Ligand Exchange ◽  
Functional Group ◽  
Atomic Layer ◽  
High Reactivity ◽  
Water Molecules ◽  
Exchange Reactions ◽  
Layer Deposition ◽  
The Right

Atomic description of ALD in systems that combine large surface area and high reactivity is key for selecting the right functional group to enhance the ligand-exchange reactions.

Dynamics and metastable surface structure of double atomic layer of water molecules and ions at the interface between KBr(c) and water

2004 ◽  
Vol 76 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K. Ichikawa ◽  
S. Sato ◽  
N. Shimomura
Keyword(s):  
Surface Structure ◽  
Vertical Motion ◽  
Atomic Layer ◽  
Water Molecules ◽  
Potassium Ions ◽  
Force Microscopy ◽  
Structure And Dynamics ◽  
Atomic Force ◽  
Bromide Ions

The metastable surface structure and dynamics of water molecules, cations, and anions at the interface between KBr(001) and water have been demonstrated from the images in situ observed in atomic resolution using atomic force microscopy. The vertical motion of potassium ions, which means their own transfer from the equilibrium sites to the upper height right on the underlying bromide ions, has been observed at the interface. They are used to be located in some steady state stabilized by their interaction with water molecules in the double atomic layer at the interface. The observed water molecules bridge two bromide ions by hydrogen bond; the water molecules are sandwiched by the potassium ions and vice versa.

Density Functional Theory Based Modeling of the Corrosion on Iron Surfaces

2013 ◽  
Vol 58 (2) ◽  
pp. 321-323 ◽  
Author(s):  
N. Nunomura ◽  
S. Sunada
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Atomic Orbital ◽  
Atomic Layer ◽  
Iron Surface ◽  
Basis Set ◽  
Water Molecules ◽  
Aqueous Corrosion ◽  
Functional Theory ◽  
Adsorption Of Water

In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.

Improvement of the humidity stability of organic–inorganic perovskite solar cells using ultrathin Al2O3layers prepared by atomic layer deposition

2015 ◽  
Vol 3 (10) ◽  
pp. 5360-5367 ◽  
Author(s):  
Xu Dong ◽  
Xiang Fang ◽  
Minghang Lv ◽  
Bencai Lin ◽  
Shuai Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Atomic Layer Deposition ◽  
Perovskite Solar Cells ◽  
Atomic Layer ◽  
Water Molecules ◽  
Inorganic Perovskite ◽  
Layer Deposition ◽  
Negative Effect ◽  
High Polarity

The high polarity of water molecules inevitably causes the decomposition of perovskites. We retard the degradation by introducing an ultrathin ALD–Al2O3layer, which has almost no negative effect on performance.

scholarly journals Diffusion Mechanism of Aqueous Solutions and Swelling of Cellulosic Fibers in Silicone Non-Aqueous Dyeing System

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 411 ◽  
Author(s):  
Liujun Pei ◽  
Yuni Luo ◽  
Xiaomin Gu ◽  
Huashu Dou ◽  
Jiping Wang
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Diffusion Mechanism ◽  
Aqueous Media ◽  
Water Molecules ◽  
Crystalline Region ◽  
Fluorescent Intensity ◽  
Cellulosic Fibers ◽  
Cellulosic Fiber ◽  
Polar Media

The main goal of this article is to study the diffusion mechanism of aqueous solutions and the swelling of cellulosic fibers in the silicone non-aqueous dyeing system via fluorescent labeling. Due to non-polar media only adsorbing on the surface of fiber, cellulosic fiber could not swell as a result of the non-polar media. However, because water molecules can diffuse into the non-crystalline region of the fiber, cellulosic fiber could swell by water which was dispersed or emulsified in a non-aqueous dyeing system. To study the diffusion mechanism of an aqueous solution in the siloxane non-aqueous dyeing system, siloxane non-aqueous media was first diffused to the cellulosic fiber because of its lower surface tension. The resulting aqueous solution took more time to diffuse the surface of the cellulosic fiber, because water molecules must penetrate the siloxane non-aqueous media film. Compared with the fluorescent intensity of the fiber surface, the siloxane film could be re-transferred to the dye bath under the emulsification of the surfactant and the mechanical force. Therefore, a longer diffusion time of the aqueous solution ensured the dyeing feasibility for cellulosic fiber in the non-aqueous dyeing system.

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