Pumping potential of a two-layer left-ventricle-like flexible-matrix-composite structure

Chanda, Avishek; Ghoneim, H.

doi:10.1016/j.compstruct.2014.11.069

Cited by 24 publications

(22 citation statements)

References 11 publications

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“…In our current work, a forced bladder expansion technique has been used to simulate the varying degrees of bladder fill. Based on the previous work by Chanda et al , a hypothetical thermal expansion coefficient ( k ) of 10 ‐4 has been specified for the bladder FE mesh elements. Every bladder element has been assigned an initial temperature ( T o ) of 0 K, and a final temperature (T) of 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, and 10,000 K to force a 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% volume expansion, respectively, for every bladder element (and thus the entire bladder), given by Equation .…”

Section: Methodsmentioning

confidence: 99%

A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall

Chanda

Unnikrishnan

Richter

et al. 2016

Numer Methods Biomed Eng

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Treatment of anterior vaginal prolapse (AVP), suffered by over 500,000 women in the USA, is a challenge in urogynecology because of the poorly understood mechanics of AVP. Recently, computational modeling combined with finite element method has been used to model AVP through the study of pelvic floor muscle and connective tissue impairments on the anterior vaginal wall (AVW). Also, the effects of pelvic organ displacements on the AVW were studied numerically. In our current work, an MRI-based full-scale biofidelic computational model of the female pelvic system composed of the urinary bladder, vaginal canal, and the uterus was developed, and a novel finite element method framework was employed to simulate vaginal tissue stiffening and also bladder filling due to expansion for the first time. A mesh convergence study was conducted to choose a computationally efficient mesh, and a non-linear hyperelastic Yeoh's material model was adopted for the study. The AVW displacements, mechanical stresses, and strains were estimated at varying degrees of bladder fills and vaginal tissue stiffening. Both bladder filling and vaginal stiffening were found to increase the stress concentration on the AVW with varying trends, which have been discussed in detail in the paper. To our knowledge, this study is the first to estimate the individual and combined effects of bladder filling and vaginal tissue stiffening due to prolapse on the AVW. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 99%

A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall

Chanda

Unnikrishnan

Richter

et al. 2016

Numer Methods Biomed Eng

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“…To develop skin like conductive polymers, two-part silicones, with Shore (Durometer) hardness of 30A and 00-10 respectively procured from Smooth-On Inc. and Polytek Inc. was used [10]. Over 30 coupons of 5 cm length, 1 cm width and 3 mm depth were fabricated for mechanical testing [10,12,13] (Figure 2). The synthetic skin composition used for the matrix material throughout the study was 45% wt.…”

Section: Fabrication and Mechanical Testingmentioning

confidence: 99%

“…29AX E250223 from Motic Inc.) was used to capture images of the test coupons before mechanical testing and a uniaxial test was conducted (on a MTS universal testing machine) to study the stress-stretch behavior of the test specimens. A well-established protocol was followed while testing the test coupons [10,12,13]. A constant strain rate of 0.4 s -1 and specimen size of 35mm x 10mm x 3mm (after clamping) was selected for all the uniaxial tests based on literature [4,5,14,15].…”

Section: Fabrication and Mechanical Testingmentioning

confidence: 99%

“…However, so far, the realistic hyperelastic material behavior of the human skin has never been simulated, which is indispensable for biomechanical testing applications such as estimating the load response of wearable technologies, cosmetic implants and biomechanical study of skin mechanics. Recently, the authors [10] developed an isotropic biofidelic skin simulant material which can accurately simulate the mechanical response of skin with different stiffnesses from different locations of the body. Soft conductive polymers have been developed in the past with carbon and metal based filler materials to advance research and testing of wearable technologies and for acquisition of biomechanical information from the human body [11].…”

Section: Introductionmentioning

confidence: 99%

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Biofidelic Conductive Synthetic Skin Composites

Chanda¹

2018

Preprint

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Skin is the first point of contact of the human body with the outer environment, and influences the biomechanics of different organ systems in normal and diseased states. Wearable electronics such as fitness tracking equipment, motion sensing devices, and advanced wearables in prosthetics and orthotics are often used to quantify the interaction of the body with the environment during different physical activities, and improve health. These wearable equipment can be bulky and a source of discomfort to the human skin with prolonged wear. To date, very few flexible polymers have been developed which can conduct electricity and be used in wearable devices. In the current work, a novel conductive synthetic skin composite system was developed, which would be indispensable for integration into wearable technologies, and also allow the biomechanical testing of the human skin for different engineering and medical applications. The mechanical behavior of this polymer can be tuned to mimic the human skin from different locations of the body with varying stiffnesses, with a phenomenal degree of accuracy. The composite system is composed of short carbon fibers dispersed in a multi part silicone based matrix material. The volume fraction of the fibers were varied to control the mechanical and electrical properties of the composite. Uniaxial tensile tests were conducted to generate stress versus strain responses of the synthetic skin composites at different fiber volume fractions, and electrical measurements were recorded at different strains. Microscopy was used to understand composite fiber orientations in unstretched and stretched states, and its effects on the electrical conductivity of the material. Additionally, non-linear material characterization models were developed to characterize the composite variants. To the best of our knowledge, such an accurate synthetic skin composite system with tailorable electrical properties has not been developed; making this state of the art in bio mimicking and functionalization of the human skin.

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“…Flexible-matrix-composites have found a wide range of applications including flexible body pumps and vibration isolation mounts. The diaphragm pumps, the jellyfish-inspired flexible pump [1], and the left-ventricle-like pump [2] are examples of compliant-body pumps. Yin and Ghoneim constructed a prototype of a flexible body pump with a very high volumetric efficiency or pumping potential (the relative volume reduction due to a relative input stroke) [3].…”

Section: Introductionmentioning

confidence: 99%

Damping Factor Estimation of a Flexible-Matrix-Composite Body Pump

Kumar¹,

Ghoneim²

2016

MSCE

Self Cite

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Two very important factors which determine the effectiveness of a pump are its volumetric and power efficiencies. Yin and Ghoneim constructed a prototype of a Flexible-Matrix-Composite (FMC) body pump with a very high volumetric efficiency or pumping potential (the relative volume reduction due to a relative input stroke). The high volumetric efficiency is attributed to the geometry of the pump's structure (hyperboloid) as well as the high negative effective Poisson's ratio of the 3-layer [θ/β/θ] flexible-matrix-composite (carbon/polyurethane) laminate adopted for the body of the pump. However, the power efficiency of the pump was not evaluated. It is the objective of the current paper to obtain an estimate of the power efficiency of the pump. The viscoelastic properties of the 3-layer FMC (carbon/polyurethane) laminate are evaluated experimentally using the Dynamic Mechanical Analyzer (DMA) as well as analytically by applying the correspondence principle together with the micro-mechanics approach. In order to obtain an estimate of the power efficiency of the FMC body pump, the axial and shear loss factors of a laminated infinitely long cylindrical tube as functions of β and θ fiber orientation angles are determined employing the Adam and Bacon approach. The analysis engenders high loss factors (greater than 0.4), which suggests that the power efficiency of the proposed pump using the 3-layer carbon/polyurethane laminate may be low.

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Pumping potential of a two-layer left-ventricle-like flexible-matrix-composite structure

Cited by 24 publications

References 11 publications

A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall

A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall

Biofidelic Conductive Synthetic Skin Composites

Damping Factor Estimation of a Flexible-Matrix-Composite Body Pump

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