Electrical Characterization of a Double-Layered Conductive Pattern with Different Crack Configurations for Durable E-Textiles

For the conductive patterns of electronic textiles (e-textiles), it is still challenging to maintain low electrical resistance, even under large or cyclic tensile deformation. This study investigated a double-layered pattern with different crack configurations as a possible solution. Patterns with single crack growth exhibit a low initial resistance and resistance change rate. In contrast, patterns with multiple crack growth maintain their conductivity under deformation, where electrical failure occurs in those with single crack growth. We considered that a double-layered structure could combine the electrical characteristics of patterns with single and multiple crack growths. In this study, each layer was theoretically designed to control the crack configuration. Then, meandering copper patterns, silver ink patterns, and their double layers were fabricated on textiles as patterns with single and multiple crack growths and double-layered patterns, respectively. Their resistance changes under the single (large) and cyclic tensile deformations were characterized. The results confirmed that the double-layered patterns maintained the lowest resistance at the high elongation rate and cycle. The resistance change rates of the meandering copper and silver ink patterns were constant, and changed monotonically against the elongation rate/cycle, respectively. In contrast, the change rate of the double-layered patterns varied considerably when electrical failure occurred in the copper layer. The change rate after the failure was much higher than that before the failure, and on the same order as that of the silver ink patterns.

Download Full-text

Interactive effect of multiple crack growth on fatigue

Theoretical and Applied Fracture Mechanics ◽

10.1016/0167-8442(95)00024-9 ◽

1995 ◽

Vol 23 (3) ◽

pp. 219-233 ◽

Cited By ~ 6

Author(s):

A. Martín-Meizoso ◽

J.M. Martínez-Esnaola ◽

M. Fuentes-Pérez

Keyword(s):

Crack Growth ◽

Interactive Effect ◽

Multiple Crack

Download Full-text

Resistance behaviour of carbon fibre-reinforced polymers subjected to lightning strikes: Experimental investigation and application

Advanced Composites Letters ◽

10.1177/2633366x19892272 ◽

2019 ◽

Vol 28 ◽

pp. 2633366X1989227 ◽

Cited By ~ 1

Author(s):

Jian Chen ◽

Zhengcai Fu ◽

Yang Zhao

Keyword(s):

Carbon Fibre ◽

Surface Resistance ◽

Inflection Point ◽

Front Surface ◽

Resistance Change ◽

Reinforced Polymers ◽

Change Rate ◽

Lightning Strikes ◽

Inflection Points ◽

Carbon Fibre Reinforced Polymers

It is difficult to monitor lightning damage to carbon fibre-reinforced polymers (CFRPs) online. This work experimentally investigates the changes associated with the electrical resistance of CFRPs subjected to lightning strikes. Two kinds of simulated lightning currents with different amplitudes in the range of 10–80 kA were injected into the CFRP samples. By measuring and comparing the changes in the struck-side (front) surface resistance, the surface resistance of the side opposite to the struck-side (back) and the oblique resistance of each sample before and after the lightning strike, it was observed that inflection points exist in the curve of the resistance change rate. The resistance decreases with increasing peak currents before the inflection point and increases when the peak current goes beyond the inflection point. The change rate of the front surface resistance is more sensitive to the lightning damage than are those of the back surface resistance and the oblique resistance. Different simulated lightning currents have approximately the same action integrals at the inflection points of resistance change rate. The characteristics indicate that resistance change detection could be a possible method for the online monitoring of CFRP lightning damage.

Download Full-text

Contribution of damage by multiple crack growth to the strain-rate sensitivity of a polycrystalline alumina at elevated temperatures

Journal of Materials Science ◽

10.1007/bf01107458 ◽

1989 ◽

Vol 24 (2) ◽

pp. 671-680 ◽

Cited By ~ 7

Author(s):

D. P. H. Hasselman ◽

A. Venkateswaran ◽

K. Y. Donaldson

Keyword(s):

Strain Rate ◽

Crack Growth ◽

Strain Rate Sensitivity ◽

Elevated Temperatures ◽

Rate Sensitivity ◽

Multiple Crack ◽

Polycrystalline Alumina

Download Full-text

Numerical Simulation of Fatigue Crack Growth for Curved Cracks Emanating from Fastener Holes in Sheets by the MVCCI Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.324-325.863 ◽

2006 ◽

Vol 324-325 ◽

pp. 863-866

Author(s):

Holger Theilig ◽

M. Goth ◽

Michael Wünsche

Keyword(s):

Numerical Simulation ◽

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Growth ◽

Plane Stress ◽

Mixed Mode ◽

Mixed Mode Loading ◽

Multiple Crack ◽

2D Structure ◽

Predictor Corrector

The paper presents the results of a continued study of curved fatigue crack growth in a multiple arbitrarily pre-cracked isotropic sheet under plane stress loading. The predictor-corrector method (PCM) was extended in order to analyse the growth of multiple crack systems in a finite 2D structure. Together with the recently proposed improved modified virtual crack closure integral (MVCCI) method we can obtain accurate SIF values also for interacting cracks, and furthermore we can simulate fatigue crack growth of multiple crack systems in plane sheets under proportional mixed mode loading conditions. As a result, the program PCCS-2D is written to run within ANSYS to simulate interacting curved cracks. In order to check the accuracy and efficiency of the proposed method several example problems are solved. Especially curved cracks emanating from loaded fastener holes in sheets are analysed.

Download Full-text

Resistance Reduction of Conductive Patterns Printed on Textile by Curing Shrinkage of Passivation Layers

Micromachines ◽

10.3390/mi11060539 ◽

2020 ◽

Vol 11 (6) ◽

pp. 539 ◽

Cited By ~ 1

Author(s):

Tomoya Koshi ◽

Ken-ichi Nomura ◽

Manabu Yoshida

Keyword(s):

Induced Resistance ◽

Tensile Deformation ◽

Curing Temperature ◽

Electronic Textiles ◽

Resistance Change ◽

Resistance Increase ◽

Resistance Reduction ◽

Passivation Layers ◽

Curing Shrinkage ◽

Initial Resistance

Directly printing conductive ink on textiles is simple and compatible with the conventional electronics manufacturing process. However, the conductive patterns thus formed often show high initial resistance and significant resistance increase due to tensile deformation. Achieving conductive patterns with low initial resistance and reduced deformation-induced resistance increase is a significant challenge in the field of electronic textiles (e-textiles). In this study, the passivation layers printed on conductive patterns, which are necessary for practical use, were examined as a possible solution. Specifically, the reduction of the initial resistance and deformation-induced resistance increase, caused by the curing shrinkage of passivation layers, were theoretically and experimentally investigated. In the theoretical analysis, to clarify the mechanism of the reduction of deformation-induced resistance increase, crack propagation in conductive patterns was analyzed. In the experiments, conductive patterns with and without shrinking passivation layers (polydimethylsiloxane) cured at temperatures of 20–120 °C were prepared, and the initial resistances and resistance increases due to cyclic tensile and washing in each case were compared. As a result, the initial resistance was reduced further by the formation of shrinking passivation layers cured at higher temperatures, and reduced to 0.45 times when the curing temperature was 120 °C. The cyclic tensile and washing tests confirmed a 0.48 and a 0.011 times reduction of resistance change rate after the 100th elongation cycle (10% in elongation rate) and the 10th washing cycle, respectively, by comparing the samples with and without shrinking passivation layers cured at 120 °C.

Download Full-text

An efficient variable-node XFEM for modeling multiple crack growth: A Matlab object-oriented implementation

Advances in Engineering Software ◽

10.1016/j.advengsoft.2019.102750 ◽

2020 ◽

Vol 140 ◽

pp. 102750 ◽

Cited By ~ 1

Author(s):

Junlei Ding ◽

Tiantang Yu ◽

Yin Yang ◽

Tinh Quoc Bui

Keyword(s):

Crack Growth ◽

Object Oriented ◽

Multiple Crack ◽

Variable Node

Download Full-text

Temperature Characteristics of a Pressure Sensor Based on BN/Graphene/BN Heterostructure

Sensors ◽

10.3390/s19102223 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2223 ◽

Cited By ~ 5

Author(s):

Mengwei Li ◽

Teng Zhang ◽

Pengcheng Wang ◽

Minghao Li ◽

Junqiang Wang ◽

...

Keyword(s):

Temperature Coefficient ◽

Pressure Sensor ◽

High Performance ◽

Pressure Sensors ◽

Resistance Change ◽

Change Rate ◽

Influence Of Temperature ◽

Temperature Characteristics ◽

Device Resistance ◽

Influence Of Temperature On

Temperature is a significant factor in the application of graphene-based pressure sensors. The influence of temperature on graphene pressure sensors is twofold: an increase in temperature causes the substrates of graphene pressure sensors to thermally expand, and thus, the graphene membrane is stretched, leading to an increase in the device resistance; an increase in temperature also causes a change in the graphene electrophonon coupling, resulting in a decrease in device resistance. To investigate which effect dominates the influence of temperature on the pressure sensor based on the graphene–boron nitride (BN) heterostructure proposed in our previous work, the temperature characteristics of two BN/graphene/BN heterostructures with and without a microcavity beneath them were analyzed in the temperature range 30–150 °C. Experimental results showed that the resistance of the BN/graphene/BN heterostructure with a microcavity increased with the increase in temperature, and the temperature coefficient was up to 0.25%°C−1, indicating the considerable influence of thermal expansion in such devices. In contrast, with an increase in temperature, the resistance of the BN/graphene/BN heterostructure without a microcavity decreased with a temperature coefficient of −0.16%°C−1. The linearity of the resistance change rate (ΔR/R)–temperature curve of the BN/graphene/BN heterostructure without a microcavity was better than that of the BN/graphene/BN heterostructure with a microcavity. These results indicate that the influence of temperature on the pressure sensors based on BN/graphene/BN heterostructures should be considered, especially for devices with pressure microcavities. BN/graphene/BN heterostructures without microcavities can be used as high-performance temperature sensors.

Download Full-text