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

Abstract

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.

Thermoelastic Damping Limited Quality Factor Enhancement and Energy Dissipation Analysis of Rectangular Plate Resonators Using Nonclassical Elasticity Theory

“…Figures 4(a)-4(c) show the variation of Q − 1 with the thickness of the beam for different boundary conditions with l/h � 0, l/h � 0.5, and l/h � 1. As l/h increases, the value of Q TED is enhanced, as shown in Figures 4(a Figures 4(a)-4(c) show the size effect variation of plate resonators for Mode-II (1,2). e variation of the quality factor with mode switching is negligible here.…”

“…Resonators. MEMS/NEMS resonators have been developed as pivotal components for sensing [1][2][3] and communication [4][5][6][7][8] applications, where increasing the sensitivity and resolution of devices is a decisive issue. Micro/nanoplates [9][10][11][12][13] are one of the paramount structures used extensively as micro/nanoresonators due to the advantages of their reduced dimensions, lower weight, surplus sensitivity, enhanced reliability, and elevated S/V ratios [14][15][16].…”

ZnO nanowires based degradable high-performance photodetectors for eco-friendly green electronics

“…Presently, there is lack of information in the risk assessment of the Ag in the form of NPs both for humans and the environment. The hydrometallurgical treatments on extracted silver particles could be used to recycle most of the disintegrated silver and enhance the circularity in electronics 62 . Further, based on the biodegradability studies, it can be argued that moisture and/or sweat could affect the PD performance and thus, the device may not be effective for wearable applications.…”