Nano-Scale Impact Dynamics of Ultra-Thin Bonded Layers

Author(s):  
Mircea Teodorescu ◽  
Stephanos Theodossiades ◽  
Homer Rahnejat

The paper highlights the complex issues involved in impact dynamics at nano-scale, prevalent in MEMS. The role of protective layers on the silicon substrate is investigated. It is found that the expected viscoelastic behavior of these layers is not activated due to the very short (almost instantaneous) impact times.

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 39
Author(s):  
Qi Chen ◽  
Zhicheng Yan ◽  
Hao Zhang ◽  
KiBuem Kim ◽  
Weimin Wang

Al-based metallic glasses have a special atomic structure and should have a unique degradation ability in azo dye solutions. The Al88Ni9Y3 (Y3), Al85Ni9Y6 (Y6) and Al82Ni9Y9 (Y9) glassy ribbons are melt spun and used in degrading methyl orange (MO) azo dye solution with adding H2O2. With increasing cY, the as-spun ribbons have an increasing GFA (glass formability) and gradually decreased the degradation rate of MO solution. TEM (transmission electron microscopy) results show that the Y3 ribbon has nano-scale crystallites, which may form the channels to transport elements to the surface for degrading the MO solution. After adding H2O2, the degradation efficiency of Al-based glasses is improved and the Y6 ribbon has formed nano-scale crystallites embedded in the amorphous matrix and it has the largest improvement in MO solution degradation. These results indicate that forming nano-scale crystallites and adding H2O2 are effective methods to improve the degradation ability of Al-based glasses in azo dye solutions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingzhe Liu ◽  
Jack Hau Yung Lo ◽  
Ye Li ◽  
Yuan Liu ◽  
Jinyu Zhao ◽  
...  

AbstractThe impact and splash of liquid drops on solid substrates are ubiquitous in many important fields. However, previous studies have mainly focused on spherical drops while the non-spherical situations, such as raindrops, charged drops, oscillating drops, and drops affected by electromagnetic field, remain largely unexplored. Using ferrofluid, we realize various drop shapes and illustrate the fundamental role of shape in impact and splash. Experiments show that different drop shapes produce large variations in spreading dynamics, splash onset, and splash amount. However, underlying all these variations we discover universal mechanisms across various drop shapes: the impact dynamics is governed by the superellipse model, the splash onset is triggered by the Kelvin-Helmholtz instability, and the amount of splash is determined by the energy dissipation before liquid taking off. Our study generalizes the drop impact research beyond the spherical geometry, and reveals the potential of using drop shape to control impact and splash.


1976 ◽  
Vol 98 (3) ◽  
pp. 463-469 ◽  
Author(s):  
C. R. Gentle ◽  
R. J. Boness

This paper describes the development of a computer program used to analyze completely the motion of a ball in a high-speed, thrust-loaded ball bearing. Particular emphasis is paid to the role of the lubricant in governing the forces and moments acting on each ball. Expressions for these forces due to the rolling and sliding of the ball are derived in the light of the latest fluid models, and estimates are also made of the cage forces applicable in this specific situation. It is found that only when lubricant viscoelastic behavior is considered do the theoretical predictions agree with existing experimental evidence.


Author(s):  
Munawar A Riyadi ◽  
Irawan D Sukawati ◽  
Teguh Prakoso ◽  
Darjat Darjat

The recent progress of dimension scaling of electronic device into nano scale has motivated the invention of alternative materials and structures. One new device that shows great potential to prolong the scaling is junctionless FET (JLFET). In contrast to conventional MOSFETs, JLFET does not require steep junction for source and drain. The device processing directly influence the performance, therefore it is crucial to understand the role of gate processing in JLFET. This paper investigates the influence of gate material and process on subthreshold performance of junctionless FET, by comparing four sets of gate properties and process techniques. The result shows that in terms of subthreshold slope, JLFET approaches near ideal value of 60 mV/decade, which is superior than the SOI FET for similar doping rate. On the other hand, the threshold value shows different tendencies between those types of device.


Author(s):  
Barbara J. Murienne ◽  
C. Thao D. Nguyen

Changes in sclera mechanical properties have been shown to play an important role in ocular diseases such as glaucoma 1,2,3 and myopia 4,5. In both diseases, those changes in mechanical behavior were observed along with changes in proteoglycan (PG) and associated glycosaminoglycan (GAG) levels, which have been shown to significantly influence the viscoelastic behavior of other tissues 6.


Sign in / Sign up

Export Citation Format

Share Document