Reliability of Flexible Wearable Band With Printed Sensors for Vital Sign Acquisition

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Hyesoo Jang ◽  
Curtis Hill ◽  
Libby Creel
Keyword(s):  
Fatigue Failure ◽  
Fem Analysis ◽  
Wearable Electronics ◽  
Multiple Components ◽  
Optical Images ◽  
Printed Sensors ◽  
Microscopy Analysis ◽  
Wearable Electronic ◽  
Number Of Cycles ◽  
Micro Controller Unit

Abstract Wearable electronics need a number of desirable attributes, such as being compact, flexible, and lightweight. Prior studies on reliability testing have examined the relationship between a flexible electronic and repetitive human body motions (i.e., stretching, bending, twisting, and folding). Such mechanical loads can cause fatigue failure in a wearable electronic. In regard to a wearable band, fatigue failure can be influenced by folding stress. This research study involved the assessment of wearable biometric bands that were calibrated and examined by a test device for folding reliability. The wearable band combines a biometric sensor unit, a micro-controller unit with a wireless connection, and a printed thermistor unit. The sensors have been calibrated by actual temperature and biometric signals. Furthermore, the folding test was conducted utilizing multiple boards. Due to multiple components and printed lines of the PCB, optical images were taken in order to confirm which parts failed and the reasons for the failures. An FEM analysis was conducted in order to understand how stress impacts the PCB and which parts are stressed during the folding process. Throughout the process, an equation was developed to predict the number of cycles necessary for reaching fatigue failure. Throughout this study, the fatigue failure analysis on folding reliability of the wearable biometric band was conducted using experimental analysis, microscopy analysis, and simulating analysis. The study provided further knowledge about the fatigue failure mechanism, which resulted from the prediction of fatigue life developed from the PCB.

scholarly journals Design framework for a seamless smart glove using a digital knitting system

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yewon Song ◽  
Seulah Lee ◽  
Yuna Choi ◽  
Sora Han ◽  
Hyuna Won ◽  
...  
Keyword(s):  
Systematic Approach ◽  
Performance Criteria ◽  
Wearable Electronics ◽  
Design Development ◽  
Performance Requirements ◽  
Development Framework ◽  
Promising Strategy ◽  
Cad Cam ◽  
Wearable Electronic ◽  
Electronic Textile

AbstractThe wearable electronics integrated with textile-based devices is a promising strategy to meet the requirements of human comfort as well as electrical performances. This research presents a design and development framework for a seamless glove sensor system using digital knitting fabrication. Based on the performance requirements of glove sensors for controlling a prosthetic hand, desirable design components include electrical conductivity, comfort, formfit, electrical sensitivity, and customizable design. These attributes are determined and achieved by applying appropriate materials and fabrication technologies. In this study, a digital knitting CAD/CAM system is utilized to meet the desired performance criteria, and two prototypes of the seamless glove sensor systems are successfully developed for the detection of both human and robotic finger motions. This digital knitting system will provide considerable potential for customized design development as well as a sustainable production process. This structured, systematic approach could be adapted in the future development of wearable electronic textile systems.

scholarly journals Foldable and washable textile-based OLEDs with a multi-functional near-room-temperature encapsulation layer for smart e-textiles

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  
Keyword(s):  
Room Temperature ◽  
Wearable Electronics ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Stable Operating ◽  
Mechanical Durability ◽  
Potential Applications ◽  
Wearable Electronic ◽  
Data Signal ◽  
Wearable Electronic Devices

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.

scholarly journals Application of Differential Entropy in Characterizing the Deformation Inhomogeneity and Life Prediction of Low-Cycle Fatigue of Metals

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1917 ◽  
Author(s):  
Mu-Hang Zhang ◽  
Xiao-Hong Shen ◽  
Lei He ◽  
Ke-Shi Zhang
Keyword(s):  
Fatigue Failure ◽  
Low Cycle Fatigue ◽  
Pure Copper ◽  
Cyclic Strain ◽  
Material Model ◽  
Cycle Fatigue ◽  
Nickel Based Superalloy ◽  
Deformation Inhomogeneity ◽  
Tension Peak ◽  
Number Of Cycles

The relation between deformation inhomogeneity and low-cycle-fatigue failure of T2 pure copper and the nickel-based superalloy GH4169 under symmetric tension-compression cyclic strain loading is investigated by using a polycrystal representative volume element (RVE) as the material model. The anisotropic behavior of grains and the strain fields are calculated by crystal plasticity, taking the Bauschinger effect into account to track the process of strain cycles of metals, and the Shannon’s differential entropies of both distributions of the strain in the loading direction and the first principal strain are employed at the tension peak of the cycles as measuring parameters of strain inhomogeneity. Both parameters are found to increase in value with increments in the number of cycles and they have critical values for predicting the material’s fatigue failure. Compared to the fatigue test data, it is verified that both parameters measured by Shannon’s differential entropies can be used as fatigue indicating parameters (FIPs) to predict the low cycle fatigue life of metal.

All-organic flexible fabric antenna for wearable electronics

2020 ◽  
Vol 8 (17) ◽  
pp. 5662-5667 ◽  
Author(s):  
Zongze Li ◽  
Sneh K. Sinha ◽  
Gregory M. Treich ◽  
Yifei Wang ◽  
Qiuwei Yang ◽  
...  
Keyword(s):  
Patch Antenna ◽  
Phase Segregation ◽  
Wearable Electronics ◽  
Electronic Networks ◽  
Conductive Phase ◽  
Wearable Electronic

An all-organic fabric patch antenna is realized with the help of nanotemplates-assisted PEDOT:PSS conductive phase segregation, paving a new way for clothing integrated wearable electronic networks.

scholarly journals Control-Based 4D Printing: Adaptive 4D-Printed Systems

2020 ◽  
Vol 10 (9) ◽  
pp. 3020 ◽  
Author(s):  
Ali Zolfagharian ◽  
Akif Kaynak ◽  
Mahdi Bodaghi ◽  
Abbas Z. Kouzani ◽  
Saleh Gharaie ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Advanced Manufacturing ◽  
Wearable Electronics ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Control Units ◽  
Printed Sensors ◽  
3D Printed ◽  
Dynamic Structures ◽  
And Control

Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analysed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.

scholarly journals Heterogeneous integration of rigid, soft, and liquid materials for self-healable, recyclable, and reconfigurable wearable electronics

2020 ◽  
Vol 6 (45) ◽  
pp. eabd0202
Author(s):  
Chuanqian Shi ◽  
Zhanan Zou ◽  
Zepeng Lei ◽  
Pengcheng Zhu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Low Cost ◽  
Well Being ◽  
Electronic System ◽  
Physical Activities ◽  
Heterogeneous Integration ◽  
Wearable Electronics ◽  
Materials Chemistry ◽  
Computer Interfaces ◽  
Human Computer Interfaces ◽  
Wearable Electronic

Wearable electronics can be integrated with the human body for monitoring physical activities and health conditions, for human-computer interfaces, and for virtual/augmented reality. We here report a multifunctional wearable electronic system that combines advances in materials, chemistry, and mechanics to enable superior stretchability, self-healability, recyclability, and reconfigurability. This electronic system heterogeneously integrates rigid, soft, and liquid materials through a low-cost fabrication method. The properties reported in this wearable electronic system can find applications in many areas, including health care, robotics, and prosthetics, and can benefit the well-being, economy, and sustainability of our society.

Evaluation of Durability of Haulage System Based on Low Fatigue Cycle Test and FEM Analysis

2015 ◽  
Vol 237 ◽  
pp. 227-232
Author(s):  
Jarosław Piekło ◽  
Maria Maj ◽  
Robert Żuczek ◽  
Adam Zachura
Keyword(s):  
Gear Tooth ◽  
Experimental Studies ◽  
Fem Analysis ◽  
Basic Research ◽  
Strength Properties ◽  
Fatigue Tests ◽  
Steel Alloy ◽  
Number Of Cycles ◽  
Highly Loaded ◽  
Haulage System

The use of the innovative design of gears segments of drivetrain engine of a longwall shearer’s haulage system with highly loaded components has improved tribological pairs of gear-tooth. The elimination of structurally complex sets of gears allowed to reduce the cost of individual component of the system, reduction of the failure rate and significantly improve the processes of repair and maintenance. The article presents the results of experimental and numerical analysis of stress and strain variables in highly loaded gear element of haulage system. The experimental studies of L20HGSNM steel alloy from which the casting was produced included basic research of strength properties of the material and two types of fatigue tests: in the range of a small number of cycles - a classic LFC and modified MLCF test. Acquired material properties of the steel alloy allowed to create material characteristics and fatigue strength curve, which were used in FEM calculations. Based on the results of numerical calculations and multiaxial criteria the fatigue life of the casting gears were evaluated.

Bone Mineral Content and Fatigue Failure of Lumbar Motion Segments in Simulated Flexed Lifting: Does Specimen Age Influence the Relationship?

2005 ◽  
Vol 49 (14) ◽  
pp. 1278-1282
Author(s):  
Sean Gallagher ◽  
William S. Marras ◽  
Alan S. Litsky ◽  
Deborah Burr
Keyword(s):  
Bone Mineral Content ◽  
Fatigue Failure ◽  
Bone Mineral ◽  
Mineral Content ◽  
Cox Regression ◽  
Data Set ◽  
Motion Segment ◽  
Segment Versus ◽  
Number Of Cycles ◽  
Cycles To Failure

This paper describes a comparison of the fatigue failure responses of older versus younger lumbar spine cadaver motion segment specimens. These specimens were repeatedly subjected to loads simulating those experienced by the spine in lifting a 9 kg load in different torso flexion postures (0, 22.5, and 45 degrees of flexion). An older sample of 36 motion segments (average age 81 years + 8 SD) is compared with a younger sample of 18 motion segments (average age: 47 years + 9 SD) with respect to the number of cycles to failure and results of survival analyses evaluating the effects of flexion and bone mineral content with and without the younger data set. Compared to the older sample of spines, the younger sample exhibited many more cycles to fatigue failure in all the torso flexion conditions (10020 versus 8267 average cycles to failure in 0 degrees flexion, 7124 versus 3262 in 22.5 degrees flexion, and 3229 versus 263 cycles to failure in 45 degrees flexion). The increased cycles to failure in young specimens is likely due to the increased bone mineral content (BMC) in younger motion segments (30.7 g + 11.1 g per motion segment versus 27.8 + 9.4 g). Cox regression analyses modeling both flexion effects and BMC indicate that betas are similar when just older spines are modeled and when younger specimens are included in the analysis. Betas for survival analysis models with and without younger specimens generally show little change for flexion (2.716 versus 2.756 for 22.5 degrees [0 degrees referent], 3.926 versus 3.380 for 45 degrees [0 degrees referent]). Bone mineral content shows a similar protective effect in both models (Betas: −0.127 versus −0.087). Overall, comparison of the models indicate that risk ratios are similar for 22.5 degrees flexion, slightly increased for 45 degrees flexion and slightly more protective influence predicted for BMC in the combined sample versus the older sample alone.

Study on Different Techniques of Fabricating Conductive Fabrics for Developing Wearable Electronics

2015 ◽  
Vol 19 (4) ◽  
pp. 11-23 ◽  
Author(s):  
L Ashok Kumar
Keyword(s):  
Research Work ◽  
Interdisciplinary Studies ◽  
Wearable Electronics ◽  
Test Rig ◽  
Electronic Products ◽  
Conductive Fabric ◽  
User Acceptability ◽  
Wearable Electronic ◽  
Different Diameters ◽  
Conductive Yarn

In recent years, interdisciplinary studies have been the mainstream in research discourses and practices. Depending on the degree of integration, the combination of electronics and textiles can be divided into three categories: wearable electronics, textronics and fibertronics. This paper discusses the development of cotton-wrapped nichrome yarn, copper core conductive yarn and optical core conductive yarn in different diameters for the production of nichrome fabric, copper core conductive fabric, optical core conductive fabric and teleintimation fabric. The yarn and the fabric were tested by a test rig especially developed for this research work. This work provides a methodology of developing conductive yarn and fabric for the development of wearable electronic products in terms of user acceptability.

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