scholarly journals Materials and Devices for Biodegradable and Soft Biomedical Electronics

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2108 ◽  
Author(s):  
Rongfeng Li ◽  
Liu Wang ◽  
Lan Yin
Keyword(s):  
Electronic Materials ◽  
Biological Tissues ◽  
Biodegradable Materials ◽  
Electronic Systems ◽  
Intimate Contact ◽  
Quality Healthcare ◽  
Integration Schemes ◽  
Healthcare Monitoring ◽  
Biomedical Electronics ◽  
Soft Electronics

Biodegradable and soft biomedical electronics that eliminate secondary surgery and ensure intimate contact with soft biological tissues of the human body are of growing interest, due to their emerging applications in high-quality healthcare monitoring and effective disease treatments. Recent systematic studies have significantly expanded the biodegradable electronic materials database, and various novel transient systems have been proposed. Biodegradable materials with soft properties and integration schemes of flexible or/and stretchable platforms will further advance electronic systems that match the properties of biological systems, providing an important step along the path towards clinical trials. This review focuses on recent progress and achievements in biodegradable and soft electronics for biomedical applications. The available biodegradable materials in their soft formats, the associated novel fabrication schemes, the device layouts, and the functionality of a variety of fully bioresorbable and soft devices, are reviewed. Finally, the key challenges and possible future directions of biodegradable and soft electronics are provided.

scholarly journals Challenges in the Fabrication of Biodegradable and Implantable Optical Fibers for Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1972
Author(s):  
Agnieszka Gierej ◽  
Thomas Geernaert ◽  
Sandra Van Vlierberghe ◽  
Peter Dubruel ◽  
Hugo Thienpont ◽  
...  
Keyword(s):  
Systematic Review ◽  
Optical Fibers ◽  
Optical Waveguides ◽  
Biomedical Applications ◽  
State Of The Art ◽  
Chemical Properties ◽  
Biological Tissues ◽  
Biodegradable Materials ◽  
Essential Properties ◽  
Optically Transparent

The limited penetration depth of visible light in biological tissues has encouraged researchers to develop novel implantable light-guiding devices. Optical fibers and waveguides that are made from biocompatible and biodegradable materials offer a straightforward but effective approach to overcome this issue. In the last decade, various optically transparent biomaterials, as well as different fabrication techniques, have been investigated for this purpose, and in view of obtaining fully fledged optical fibers. This article reviews the state-of-the-art in the development of biocompatible and biodegradable optical fibers. Whilst several reviews that focus on the chemical properties of the biomaterials from which these optical waveguides can be made have been published, a systematic review about the actual optical fibers made from these materials and the different fabrication processes is not available yet. This prompted us to investigate the essential properties of these biomaterials, in view of fabricating optical fibers, and in particular to look into the issues related to fabrication techniques, and also to discuss the challenges in the use and operation of these optical fibers. We close our review with a summary and an outline of the applications that may benefit from these novel optical waveguides.

scholarly journals A discrete fibre dispersion method for excluding fibres under compression in the modelling of fibrous tissues

2018 ◽  
Vol 15 (138) ◽  
pp. 20170766 ◽  
Author(s):  
Kewei Li ◽  
Ray W. Ogden ◽  
Gerhard A. Holzapfel
Keyword(s):  
Strain Energy ◽  
Dispersion Model ◽  
Substantial Reduction ◽  
Uniaxial Extension ◽  
Biological Tissues ◽  
Fibre Direction ◽  
Fibre Density ◽  
Integration Schemes ◽  
Simple Tension ◽  
Elementary Area

Recently, micro-sphere-based methods derived from the angular integration approach have been used for excluding fibres under compression in the modelling of soft biological tissues. However, recent studies have revealed that many of the widely used numerical integration schemes over the unit sphere are inaccurate for large deformation problems even without excluding fibres under compression. Thus, in this study, we propose a discrete fibre dispersion model based on a systematic method for discretizing a unit hemisphere into a finite number of elementary areas, such as spherical triangles. Over each elementary area, we define a representative fibre direction and a discrete fibre density. Then, the strain energy of all the fibres distributed over each elementary area is approximated based on the deformation of the representative fibre direction weighted by the corresponding discrete fibre density. A summation of fibre contributions over all elementary areas then yields the resultant fibre strain energy. This treatment allows us to exclude fibres under compression in a discrete manner by evaluating the tension–compression status of the representative fibre directions only. We have implemented this model in a finite-element programme and illustrate it with three representative examples, including simple tension and simple shear of a unit cube, and non-homogeneous uniaxial extension of a rectangular strip. The results of all three examples are consistent and accurate compared with the previously developed continuous fibre dispersion model, and that is achieved with a substantial reduction of computational cost.

scholarly journals Organic Bioelectronics: Materials and Biocompatibility

2018 ◽  
Vol 19 (8) ◽  
pp. 2382 ◽  
Author(s):  
Krishna Feron ◽  
Rebecca Lim ◽  
Connor Sherwood ◽  
Angela Keynes ◽  
Alan Brichta ◽  
...  
Keyword(s):  
Ionic Conduction ◽  
Electronic Materials ◽  
Biological Tissues ◽  
Charge Carriers ◽  
Organic Electronic ◽  
Inorganic Semiconductors ◽  
Organic Electronic Materials ◽  
Wide Range ◽  
Organic Bioelectronics ◽  
Conduction Properties

Organic electronic materials have been considered for a wide-range of technological applications. More recently these organic (semi)conductors (encompassing both conducting and semi-conducting organic electronic materials) have received increasing attention as materials for bioelectronic applications. Biological tissues typically comprise soft, elastic, carbon-based macromolecules and polymers, and communication in these biological systems is usually mediated via mixed electronic and ionic conduction. In contrast to hard inorganic semiconductors, whose primary charge carriers are electrons and holes, organic (semi)conductors uniquely match the mechanical and conduction properties of biotic tissue. Here, we review the biocompatibility of organic electronic materials and their implementation in bioelectronic applications.

scholarly journals Electronic Multiscale Hybrid Materials: Sinter-Free Inks, Printed Transparent Grids, and Soft Devices

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 24
Author(s):  
Tobias Kraus
Keyword(s):  
Radio Frequency Identification ◽  
Electronic Materials ◽  
Conductive Polymer ◽  
Metal Nanowires ◽  
Flexible Sensors ◽  
Semiconductor Nanoparticle ◽  
Frequency Identification ◽  
Polymer Foils ◽  
Soft Electronics ◽  
Polymer Shells

Hybrid electronic materials combine the excellent electronic properties of metals and semiconductors with the mechanical flexibility, ease of processing, and optical transparency of polymers. This talk will discuss hybrids that combine organic and inorganic components at different scales. Metallic and semiconductor nanoparticle cores are coated with conductive polymer shells to create “hybrid inks” that can be inkjet-printed and form conductive leads without any sintering step. Transparent electrodes are printed using ultrathin metal nanowires with core diameters below 2 nm. The chemically synthesized wires spontaneously form percolating structures when patterned with a soft stamp; this rapidly yields optically transparent grid electrodes, even on demanding soft substrates. These new hybrid electronic materials enable the fabrication of soft electronics, including flexible sensors on polymer foils, radio-frequency identification (RFID) antennae on cardboard, and soft human–machine interfaces. Selected devices will be covered at the end of the talk.

scholarly journals Battery-free, skin-interfaced microfluidic/electronic systems for simultaneous electrochemical, colorimetric, and volumetric analysis of sweat

2019 ◽  
Vol 5 (1) ◽  
pp. eaav3294 ◽  
Author(s):  
Amay J. Bandodkar ◽  
Philipp Gutruf ◽  
Jungil Choi ◽  
KunHyuck Lee ◽  
Yurina Sekine ◽  
...  
Keyword(s):  
Sweat Rate ◽  
Form Factors ◽  
Volumetric Analysis ◽  
Physiological Status ◽  
Electronic Systems ◽  
Narrow Scope ◽  
Integration Schemes ◽  
Sensing Platform ◽  
And Performance ◽  
Electronic Sensing

Wearable sweat sensors rely either on electronics for electrochemical detection or on colorimetry for visual readout. Non-ideal form factors represent disadvantages of the former, while semiquantitative operation and narrow scope of measurable biomarkers characterize the latter. Here, we introduce a battery-free, wireless electronic sensing platform inspired by biofuel cells that integrates chronometric microfluidic platforms with embedded colorimetric assays. The resulting sensors combine advantages of electronic and microfluidic functionality in a platform that is significantly lighter, cheaper, and smaller than alternatives. A demonstration device simultaneously monitors sweat rate/loss, pH, lactate, glucose, and chloride. Systematic studies of the electronics, microfluidics, and integration schemes establish the key design considerations and performance attributes. Two-day human trials that compare concentrations of glucose and lactate in sweat and blood suggest a potential basis for noninvasive, semi-quantitative tracking of physiological status.

scholarly journals Correlation-driven machine learning for accelerated reliability assessment of solder joints in electronics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vahid Samavatian ◽  
Mahmud Fotuhi-Firuzabad ◽  
Majid Samavatian ◽  
Payman Dehghanian ◽  
Frede Blaabjerg
Keyword(s):  
Machine Learning ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Reliability Assessment ◽  
Electronic Systems ◽  
Learning Framework ◽  
Useful Lifetime

Abstract The quantity and variety of parameters involved in the failure evolutions in solder joints under a thermo-mechanical process directs the reliability assessment of electronic devices to be frustratingly slow and expensive. To tackle this challenge, we develop a novel machine learning framework for reliability assessment of solder joints in electronic systems; we propose a correlation-driven neural network model that predicts the useful lifetime based on the materials properties, device configuration, and thermal cycling variations. The results indicate a high accuracy of the prediction model in the shortest possible time. A case study will evaluate the role of solder material and the joint thickness on the reliability of electronic devices; we will illustrate that the thermal cycling variations strongly determine the type of damage evolution, i.e., the creep or fatigue, during the operation. We will also demonstrate how an optimal selection of the solder thickness balances the damage types and considerably improves the useful lifetime. The established framework will set the stage for further exploration of electronic materials processing and offer a potential roadmap for new developments of such materials.

Mechanics of Epidermal Electronics

2012 ◽  
Vol 79 (3) ◽  
Author(s):  
Shuodao Wang ◽  
Ming Li ◽  
Jian Wu ◽  
Dae-Hyeong Kim ◽  
Nanshu Lu ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic System ◽  
Van Der Waals Interactions ◽  
Electronic Systems ◽  
Element Analysis ◽  
Intimate Contact ◽  
Design And Optimization ◽  
Premature Babies ◽  
Machine Interface ◽  
Mechanics Concepts

Epidermal electronic system (EES) is a class of integrated electronic systems that are ultrathin, soft, and lightweight, such that it could be mounted to the epidermis based on van der Waals interactions alone, yet provides robust, intimate contact to the skin. Recent advances on this technology will enable many medical applications such as to monitor brain or heart activities, to monitor premature babies, to enhance the control of prosthetics, or to realize human-machine interface. In particular, the contact between EES and the skin is key to high-performance functioning of the above applications and is studied in this paper. The mechanics concepts that lead to successful designs of EES are also discussed. The results, validated by finite element analysis and experimental observations, provide simple, analytical guidelines for design and optimization of EES with various possible functionalities.

scholarly journals Skin-Integrated Electromechanical Systems for Characterization of Deep Tissue Biomechanics

2020 ◽  
Author(s):  
John Rogers ◽  
Enming Song ◽  
Zhaoqian Xie ◽  
Wubin Bai ◽  
Haiwen Luan ◽  
...  
Keyword(s):  
Depth Profiling ◽  
Biological Tissues ◽  
Dynamic Monitoring ◽  
Electronic Systems ◽  
Strain Sensing ◽  
Deep Tissue ◽  
Active Devices ◽  
Tissue Biomechanics ◽  
And Performance

Abstract Compact electronic systems that perform rapid, precise mechanical characterization of living biological tissues have important potential uses in monitoring and diagnosing various types of human-health disorders. Active devices that perform high-precision, real-time evaluations of deep tissue structures (millimeter-scale) in a precise, digital and non-invasive fashion could complement capabilities of recently-reported approaches for sensing tissue biomechanics at superficial depths (typically micrometer-scale). This paper introduces a miniature electromagnetic platform that combines a vibratory actuator with a soft strain-sensing sheet for determining the Young’s modulus of soft biological tissues, with specific focus on skin. Experimental and computational studies establish the operational principles and performance attributes through evaluations of synthetic and biological materials, including human skin at various body locations across healthy subject volunteers. The results demonstrate dynamic monitoring of elastic modulus at characteristic depths between ~1 and ~8 mm, depending on the sensor designs. Arrays of such devices support capabilities in both depth profiling and spatial mapping. Clinical studies on patients with skin disorders highlight potential for accurate targeting of lesions associated with psoriasis, as examples of practical medical utility.

scholarly journals Partial squeeze film levitation modulates fingertip friction

2016 ◽  
Vol 113 (33) ◽  
pp. 9210-9215 ◽  
Author(s):  
Michaël Wiertlewski ◽  
Rebecca Fenton Friesen ◽  
J. Edward Colgate
Keyword(s):  
Glass Plate ◽  
Soft Materials ◽  
Biological Tissues ◽  
Friction Reduction ◽  
Squeeze Film ◽  
Intimate Contact ◽  
Transverse Waves ◽  
Frustrated Total Internal Reflection ◽  
Interfacial Separation ◽  
Interfacial Gap

When touched, a glass plate excited with ultrasonic transverse waves feels notably more slippery than it does at rest. To study this phenomenon, we use frustrated total internal reflection to image the asperities of the skin that are in intimate contact with a glass plate. We observed that the load at the interface is shared between the elastic compression of the asperities of the skin and a squeeze film of air. Stroboscopic investigation reveals that the time evolution of the interfacial gap is partially out of phase with the plate vibration. Taken together, these results suggest that the skin bounces against the vibrating plate but that the bounces are cushioned by a squeeze film of air that does not have time to escape the interfacial separation. This behavior results in dynamic levitation, in which the average number of asperities in intimate contact is reduced, thereby reducing friction. This improved understanding of the physics of friction reduction provides key guidelines for designing interfaces that can dynamically modulate friction with soft materials and biological tissues, such as human fingertips.

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

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