Bio-inspired Studies on Adhesion of a Thin Film on a Rigid Substrate

Bio-inspired Studies on Adhesion of a Thin Film on a Rigid Substrate
Author: Zhilong Peng
Publisher: Springer
Total Pages: 107
Release: 2015-04-07
Genre: Technology & Engineering
ISBN: 3662469553

Download Bio-inspired Studies on Adhesion of a Thin Film on a Rigid Substrate Book in PDF, Epub and Kindle

The thesis systematically investigates the factors which influence many animals’ robust adhesion abilities and micro-reversible adhesion mechanisms, including the geometric principles of their adhesion, relative humidity, surface roughness and pre-tension. Studies exploring biological adhesion mechanisms are not only of great significance for the design of advanced adhesive materials and adhesion systems for micro-climbing robots, but also very helpful for resolving the problem of adhesion failure in MEMS/NEMS.

Bio-inspired Structured Adhesives

Bio-inspired Structured Adhesives
Author: Lars Heepe
Publisher: Springer
Total Pages: 357
Release: 2017-07-21
Genre: Technology & Engineering
ISBN: 3319591142

Download Bio-inspired Structured Adhesives Book in PDF, Epub and Kindle

This book deals with the adhesion, friction and contact mechanics of living organisms. Further, it presents the remarkable adhesive abilities of the living organisms which inspired the design of novel micro- and nanostructured adhesives that can be used in various applications, such as climbing robots, reusable tapes, and biomedical bandages. The technologies for both the synthesis and construction of bio-inspired adhesive micro- and nanostructures, as well as their performance, are discussed in detail. Representatives of several animal groups, such as insects, spiders, tree frogs, and lizards, are able to walk on (and therefore attach to) tilted, vertical surfaces, and even ceilings in different environments. Studies have demonstrated that their highly specialized micro- and nanostructures, in combination with particular surface chemistries, are responsible for this impressive and reversible adhesion. These structures can maximize the formation of large effective contact areas on surfaces of varying roughness and chemical composition under different environmental conditions.

Science and Global Challenges of the 21st Century - Science and Technology

Science and Global Challenges of the 21st Century - Science and Technology
Author: Alvaro Rocha
Publisher: Springer Nature
Total Pages: 1146
Release: 2021-10-13
Genre: Technology & Engineering
ISBN: 3030894770

Download Science and Global Challenges of the 21st Century - Science and Technology Book in PDF, Epub and Kindle

This book comprises the proceedings of the International Perm Forum “Science and Global Challenges of the 21st Century” held on October 18th – 23rd, 2021, at Perm State University, Perm, Russia. Global challenges, which determine the main trends in the development of social and economic life in the XXI century, require the integration of specialists in various fields of knowledge. That is why the main principle of this edition is interdisciplinarity, the formation of end-to-end innovation chains, including fundamental and applied research, and the wide application of smart innovations, networks, and information technologies. The authors seek to find synergy between technologies and such fields as computer science, geosciences, biology, linguistics, social studies, historical studies, and economics. The book is of interest to researchers seeking nontrivial solutions at the interface of sciences, digital humanities, computational linguistics, cognitive studies, machine learning, and others.

Controllable Adhesion in a Bio-inspired Film-terminated Fibrillar Surface

Controllable Adhesion in a Bio-inspired Film-terminated Fibrillar Surface
Author: Nichole Kristina Nadermann
Publisher:
Total Pages: 143
Release: 2012
Genre:
ISBN:

Download Controllable Adhesion in a Bio-inspired Film-terminated Fibrillar Surface Book in PDF, Epub and Kindle

In this dissertation we present work on the development, characterization, and analysis of an easy-to-fabricate, reusable bioinspired switchable adhesive that consists of a film-terminated fibrillar layer atop a substrate. We use a dynamic rod model and stability analysis to define and analyze the buckling of a fibril subjected to a prescribed shear displacement and a constant normal compressive force. Following this analysis, we present work on the switchable adhesive: a film-terminated fibrillar interface with two metastable states. In the first state, a thin film spanning the fibrillar surface results in strongly enhanced adhesion due to crack-trapping. In the second state, the thin film collapses onto the substrate between fibrils and resembles a rough surface. We perform indentation experiments (pull-off and adhesion hysteresis), which demonstrate differences in the adhesive response of the two states. We show that the adhesive state has a pull-off load up to 70 times higher than the non-adhesive state and has up to 20 times larger adhesion hysteresis. Friction experiments show that in the collapsed state there is no static friction peak and that even in sliding friction, which is not enhanced for the adhesive state over the control samples (flat, unstructured PDMS), the collapsed state exhibits much lower sliding friction forces. We determine the pressure-to-collapse the thin film to switch from the adhesive to the non-adhesive state using hydrostatic pressure experiments. Finally, we perform both linear plate and von Kärman plate analyses on the thin film as it deforms under an applied pressure to gain insight into both bistability and the pressure required to collapse the thin film and in doing so, turn off the adhesion. We find that the von Kärman plate theory more accurately captures the pressure required to initiate collapse of the thin film onto the substrate, most likely because of the large deflections taking place during collapse. To account for pressurization that occurs in our sealed samples during hydrostatic pressure experiments, we model the rate dependence in the hydrostatic pressure experiments. Pressurization and diffusion of gas through the thin film reduces the dependence on interfibrillar spacing.

Advances in Bionanotechnology Research and Application: 2013 Edition

Advances in Bionanotechnology Research and Application: 2013 Edition
Author:
Publisher: ScholarlyEditions
Total Pages: 558
Release: 2013-06-21
Genre: Technology & Engineering
ISBN: 1481681818

Download Advances in Bionanotechnology Research and Application: 2013 Edition Book in PDF, Epub and Kindle

Advances in Bionanotechnology Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Biochips. The editors have built Advances in Bionanotechnology Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Biochips in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Advances in Bionanotechnology Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Deformation and Adhesion of Soft Composite Systems for Bio-inspired Adhesives and Wrinkled Surface Fabrication

Deformation and Adhesion of Soft Composite Systems for Bio-inspired Adhesives and Wrinkled Surface Fabrication
Author: Michael Imburgia
Publisher:
Total Pages:
Release: 2017
Genre:
ISBN:

Download Deformation and Adhesion of Soft Composite Systems for Bio-inspired Adhesives and Wrinkled Surface Fabrication Book in PDF, Epub and Kindle

The study of soft material deformation and adhesion has broad applicability to industries ranging from automobile tires to medical prosthetics and implants. When a mechanical load is imposed on a soft material system, a variety of issues can arise, including non-linear deformations at interfaces between soft and rigid components. The work presented in this dissertation embraces the occurrence of these non-linear deformations, leading to the design of functional systems that incorporate a soft elastomer layer with application to bio-inspired adhesives and wrinkled surface fabrication. Understanding the deformation of a soft elastomer layer and how the system loading and geometry influence non-linear mechanical transitions, including interfacial failure and surface buckling, are crucial for predicting the performance of the mechanical system. This dissertation focuses on three soft composite systems of particular interest: (1) a multi-component, multiple adhesive contact surface device that allows for control of reversible adhesive force with geometric arrangement, (2) a confined isolated shear contact and an elastomeric coating, where the deformation and adhesion scale with the degree of confinement, and (3) a thin film lamination technique involving a soft substrate, where surface wrinkles are created and tuned in a continuous manner by controlling interfacial strains via applied contact load and substrate curvature. We first study the deformation and adhesion of a multi-component fabric-elastomer system with multiple adhesive contacts, or "digits". We conduct lap adhesion experiments in a model three digit system, finding that increasing angular spacing between adhesive digits increases system compliance and attenuates adhesive force capacity. To describe these findings we develop several relationships between system loading, materials properties, and geometry. We develop an equation which describes the relationship of system compliance with individual digit compliance and angular spacing between adhesive digits that agrees well with experimental data. Additionally, we derive equations for adhesive force capacity in a multiple adhesive contact system that agree well with experimental data. These explicit equations not only relate angular spacing with force capacity, but include critical strain energy release rate, digit compliance, and contact area. The equations derived and verified in this study will lead to more complex adhesive device design, as well as provide a foundation for studying the biomechanics of animals that use adhesion for locomotion. Next, we examine the deformation and adhesion of a rigid punch contacting and shearing a thin elastic coating. Using experiment we find that increasing confinement leads to a decrease in compliance and an increase in adhesive force capacity. We develop an explicit, semi-empirical equation with the help of finite element analysis to describe the influence of confinement ratio on shear compliance. This derived equation agrees with our experimental data, with the exception of a few data points that deviate due to a pronounced normal force component. Additionally, we derive an equation for adhesive force capacity as a function of confinement, elastic coating modulus, and critical strain energy release rate. We find experimentally that an increase in adhesive force capacity was largely dictated by an increase in confinement, with some additional contributions attributed to dissipative processes confined to the adhesive crack tip. These equations will serve as a guide for decoupling the contributions of geometry and materials parameters to adhesive force in systems involving a thin elastic layer. Lastly, we develop a fabrication technique that transforms the existing manufacturing process of film lamination to create tunable wrinkled surfaces in a thin film/soft elastomer composite. We conduct experiments to find that the process parameters of applied contact load and roller curvature can be used to control wrinkle aspect ratio. Our experimental results convey that increasing applied contact load and decreasing roller radius lead to an increase in wrinkle amplitude. Using both experimental results and finite element analysis, we develop a relation between wrinkle aspect ratio and the process parameters of applied contact load and roller curvature. This explicit equation allows us to predict the change in wrinkle amplitude for a given materials system as process parameters are tuned using our modified film lamination technique. Wrinkled surface technology has been envisioned in many applications ranging from optoelectronics to enhanced adhesives. The technique presented here to tune wrinkle size in a continuous process can lead to the large scale manufacturing of these previously proposed wrinkling technologies.

Adhesion Aspects of Thin Films

Adhesion Aspects of Thin Films
Author: K. L. Mittal
Publisher: VSP
Total Pages: 288
Release: 2001-04-03
Genre: Science
ISBN: 9789067643382

Download Adhesion Aspects of Thin Films Book in PDF, Epub and Kindle

This book chronicles the proceedings of the First International Symposium on Adhesion Aspects of Thin Films, held in Newark, New Jersey, October 28-29, 1999. Films and coatings are used for a variety of purposes – decorative, protective, functional, etc. – in a host of applications. Irrespective of the intended function or application of a film or a coating, their adequate adhesion to the underlying substrates is of cardinal importance. Concomitantly, the need to understand the factors controlling adhesion and to tailor adhesion to a desired level is quite patent. This book contains a total of 16 papers, which were presented by researchers from academia, industry and other laboratories, and have been rigorously peer reviewed, suitably revised and properly edited before inclusion. The topics covered include: mechanisms, origin, evolution and measurement of stresses in thin films; surface stress effects on the intrinsic stress; various factors affecting stresses in thin films; delamination of coatings caused by residual stress; effects of surface treatments on the adhesion of metallic films; adhesion of CVD diamond to carbide cutting inserts; effect of carbon contaminant on adhesion of aluminum films; effect of interlayers on adhesion of ceramic coatings; effect of residual stress on adhesion and wear resistance of hard coatings; tribological properties of ceramic films; oxide layers as barrier coatings on a plastic substrate; adhesion aspects of organic coatings to metals; and adhesion of thin plasma polymerized fluorocarbon films.This book, providing a commentary on the current state of knowledge of adhesion of thin films, will be useful to anyone interested in thin films and will provide ideas on how to improve or tailor adhesion of a film or a coating for a given situation.

Adhesion and Friction in Biological Systems

Adhesion and Friction in Biological Systems
Author: Stanislav N. Gorb
Publisher: Springer
Total Pages: 296
Release: 2016-05-01
Genre:
ISBN: 9789401778732

Download Adhesion and Friction in Biological Systems Book in PDF, Epub and Kindle

This book explores biological systems with surface specializations which increase or decrease friction and adhesion. Studies examine snake skin and adhesive pads in animals, as well as anti-adhesive and adhesive surfaces of plants, among many other examples.

Adhesion Aspects of Thin Films, volume 2

Adhesion Aspects of Thin Films, volume 2
Author: Kash L. Mittal
Publisher: CRC Press
Total Pages: 241
Release: 2005-05-06
Genre: Science
ISBN: 9067644218

Download Adhesion Aspects of Thin Films, volume 2 Book in PDF, Epub and Kindle

This volume documents the proceedings of the International Symposium on Adhesion Aspects of Thin Films (including Adhesion Measurement, and Metallized plastics) held in Orlando, FL, December 15-16, 2003. This volume is divided into three parts. Part 1 “General Papers”; Part 2 “Metallized Plastics”; and Part 3 “Adhesion Measurement”. The topics covered include: Factors influencing adhesion of thin films; relevance of stresses in film adhesion; surface effects on intrinsic thin film stresses; adhesion improvement; hemocompatibility of DLC coatings; thin films of various materials on a host of substrates; thin polymer films; surface modification of polymers; adhesion of metal films on polymers; investigation of metal-polymer interactions; adhesion measurement; scratch test; microscratch test; and abrasion and durability of thin films.