scholarly journals Bending Strain and Bending Fatigue Lifetime of Flexible Metal Electrodes on Polymer Substrates

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2490 ◽  
Author(s):  
Tae-Wook Kim ◽  
Jong-Sung Lee ◽  
Young-Cheon Kim ◽  
Young-Chang Joo ◽  
Byoung-Joon Kim
Keyword(s):  
Flexible Electronics ◽  
Electrical Resistance ◽  
Metal Electrode ◽  
Substrate Thickness ◽  
Metal Electrodes ◽  
Fatigue Lifetime ◽  
Bending Fatigue ◽  
Bending Strain ◽  
Bending Fatigue Test ◽  
Flexible Metal

As the technology of flexible electronics has remarkably advanced, the long-term reliability of flexible devices has attracted much attention, as it is an important factor for such devices in reaching real commercial viability. To guarantee the bending fatigue lifetime, the exact evaluation of bending strain and the change in electrical resistance is required. In this study, we investigated the bending strains of Cu thin films on flexible polyimide substrates with different thicknesses using monolayer and bilayer bending models and monitored the electrical resistance of the metal electrode during a bending fatigue test. For a thin metal electrode, the bending strain and fatigue lifetime were similar regardless of substrate thickness, but for a thick metal film, the fatigue lifetime was changed by different bending strains in the metal electrode according to substrate thickness. To obtain the exact bending strain distribution, we conducted a finite-element simulation and compared the bending strains of thin and thick metal structures. For thick metal electrodes, the real bending strain obtained from a bilayer model or simulation showed values much different from those from a simple monolayer model. This study can provide useful guidelines for developing highly reliable flexible electronics.

Design of Bending Fatigue Machine for Flexible Electronics

2011 ◽  
Vol 383-390 ◽  
pp. 483-489 ◽  
Author(s):  
Hu Wen Cao ◽  
Ping Yang ◽  
Bi Zhen Bao
Keyword(s):  
Motor Control ◽  
Fatigue Test ◽  
Flexible Electronics ◽  
Stepper Motor ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Precision Control ◽  
Bending Fatigue ◽  
Detection Circuit ◽  
Bending Fatigue Test

According to the current requirements of bending fatigue test for flexible electronics, a bending fatigue machine based on SCM (single chip Microcomputer) has been designed. using stepper motor driving screw nut body as loading mechanism, improve the accuracy of the structure effectively by gaps eliminator, and achieve the requirement of precision control by using fraction driving technology in the motor control. Photoelectric counter and electrical signals detection circuit have also been designed to achieve unattended function. This design plays an important role in the following testing process.

A FAST ROTATING BENDING FATIGUE TEST MACHINE

2017 ◽  
Author(s):  
Marco Antonio Meggiolaro ◽  
Jaime T P Castro ◽  
Rodrigo de Moura Nogueira
Keyword(s):  
Fatigue Test ◽  
Test Machine ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Fast Rotating

Electrical Failure and Damage Analysis of Multi-Layer Metal Films on Flexible Substrate during Cyclic Bending Deformation

2011 ◽  
Author(s):  
Byoung-Joon Kim ◽  
Hae-A-Seul Shin ◽  
In-Suk Choi ◽  
Young-Chang Joo
Keyword(s):  
Fatigue Resistance ◽  
Electrical Resistance ◽  
Metal Film ◽  
Flexible Substrate ◽  
Resistance Change ◽  
Cyclic Bending ◽  
Capping Layer ◽  
Bending Strain ◽  
Cu Film ◽  
Electrical Resistance Change

Abstract The electrical resistance Cu film on flexible substrate was investigated in cyclic bending deformation. The electrical resistance of 1 µm thick Cu film on flexible substrate increased up to 120 % after 500,000 cycles in 1.1 % tensile bending strain. Crack and extrusion were observed due to the fatigue damage of metal film. Low bending strain did not cause any damage on metal film but higher bending strain resulted in severe electrical and mechanical damage. Thinner film showed higher fatigue resistance because of the better mechanical property of thin film. Cu film with NiCr under-layer showed poorer fatigue resistance in tensile bending mode. Ni capping layer did not improve the fatigue resistance of Cu film, but Al capping layer suppressed crack formation and lowered electrical resistance change. The NiCr under layer, Ni capping layer, and Al capping layer effect on electrical resistance change of Cu film was compared with Cu only sample.

A Study onP-S-NCurve for Rotating Bending Fatigue Test for Bearing Steel

2008 ◽  
Vol 51 (2) ◽  
pp. 166-172 ◽  
Author(s):  
Katsuji Tosha ◽  
Daisuke Ueda ◽  
Hirokazu Shimoda ◽  
Shigeo Shimizu
Keyword(s):  
Fatigue Test ◽  
Bearing Steel ◽  
Bending Fatigue ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

Method Research on Bending Fatigue Test of Vehicle Steering Wheel

2014 ◽  
Vol 989-994 ◽  
pp. 3029-3032
Author(s):  
Xun Jiong Xu ◽  
Liang Tian
Keyword(s):  
Fatigue Test ◽  
New Method ◽  
Steering Wheel ◽  
Bending Fatigue ◽  
Bending Fatigue Test

Through researches a new method of bending fatigue test of vehicle steering wheel was raised in this paper. The new method is closer to the actual using condition of vehicle steering wheel, which enhances the reliability of the test.

scholarly journals Solution-processable electrode-material embedding in dynamically inscribed nanopatterns (SPEEDIN) for continuous fabrication of durable flexible devices

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wonseok Lee ◽  
Hyoungseok Chae ◽  
Dong Kyo Oh ◽  
Minyoung Lee ◽  
Hyunsoo Chun ◽  
...  
Keyword(s):  
Electrode Material ◽  
Flow Line ◽  
Metal Electrode ◽  
Metal Nanoparticle ◽  
Power Efficient ◽  
Flexible Devices ◽  
Mechanical Deformations ◽  
Solution Processable ◽  
Flexible Metal ◽  
Continuous Fabrication

AbstractA facile and scalable lithography-free fabrication technique, named solution-processable electrode-material embedding in dynamically inscribed nanopatterns (SPEEDIN), is developed to produce highly durable electronics. SPEEDIN uniquely utilizes a single continuous flow-line manufacturing process comprised of dynamic nanoinscribing and metal nanoparticle solution coating with selective embedding. Nano- and/or micro-trenches are inscribed into arbitrary polymers, and then an Ag nanoparticle solution is dispersed, soft-baked, doctor-bladed, and hard-baked to embed Ag micro- and nanowire structures into the trenches. Compared to lithographically embossed metal structures, the embedded SPEEDIN architectures can achieve higher durability with comparable optical and electrical properties and are robust and power-efficient even under extreme stresses such as scratching and bending. As one tangible application of SPEEDIN, we demonstrate a flexible metal electrode that can operate at 5 V at temperatures up to 300 °C even under the influence of harsh external stimuli. SPEEDIN can be applied to the scalable fabrication of diverse flexible devices that are reliable for heavy-duty operation in harsh environments involving high temperatures, mechanical deformations, and chemical hazards.

Experimental Study of the High Cycle Fatigue of Thin Film Metal on Polyethylene Terephthalate for Flexible Electronics Applications

2009 ◽  
Author(s):  
Khalid Alzoubi ◽  
Susan Lu ◽  
Bahgat Sammakia ◽  
Mark Poliks
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Flexible Electronics ◽  
Electrical Resistance ◽  
Thermal Stresses ◽  
Electronic Systems ◽  
Total Width ◽  
Flexible Substrates ◽  
Polyethylene Naphthalate

Flexible electronics represent an emerging area in the electronics packaging and systems integration industry with the potential for new product development and commercialization in the near future. Manufacturing electronics on flexible substrates will produce low cost devices that are rugged, light, and flexible. However, electronic systems are vulnerable to failures caused by mechanical and thermal stresses. For electronic systems on flexible substrates repeated stresses below the ultimate tensile strength or even below the yield strength will cause failures in the thin films. It is known that mechanical properties of thin films are different from those of bulk materials; so, it is difficult to extrapolate bulk material properties on thin film materials. The objective of this work is to study the behavior of thin-film metal coated flexible substrates under high cyclic bending fatigue loading. Polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are widely used substrates in the fabrication of microelectronic devices. Factors affecting the fatigue life of thin-film coated flexible substrates were studied, including thin film thickness, temperature, and humidity. A series of experiments for sputter-deposited copper on PET substrates were performed. Electrical resistance and crack growth rate were monitored during the experiments at specified time intervals. High magnification images were obtained to observe the crack initiation and propagation in the metal film. Statistical analysis based on design of experiments concepts was performed to identify the main factors and factor’s interaction that affect the life of a thin-film coated substrate. The results of the experiments showed that the crack starts in the middle of the sample and slowly grows toward the edges. Electrical resistance increases slightly during the test until the crack length covers about 90% of the total width of the sample where a dramatic increase in the resistance takes place.

Simulation of the vertical bending fatigue test of a five-link rear axle housing

2012 ◽  
Vol 13 (6) ◽  
pp. 923-932 ◽  
Author(s):  
X. Wang ◽  
W. Xu ◽  
Y. Huang ◽  
M. Zhong ◽  
H. Fan
Keyword(s):  
Fatigue Test ◽  
Rear Axle ◽  
Bending Fatigue ◽  
Bending Fatigue Test
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