Bhushan B. Nanotribology and Nanomechanics: An Introduction

Подождите немного. Документ загружается.

Nanotribology and Nanomechanics

2nd edition

Bharat Bhushan

Editor

Nanotribology

and Nanomechanics

An Introduction

2nd edition

123

Professor Bharat Bhushan

Ohio Eminent Scholar and The Howard D. Winbigler Professor

Director, Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLB

)

201 W. 19th Avenue

Ohio State University

Columbus, Ohio 43210-1142

USA

bhushan.2@osu.edu

ISBN 978-3-540-77607-9

DOI 10.1007/978-3-540-77608-6

e-ISBN 978-3-540-77608-6

Library of Congress Control Number: 2008921404

This work is subject to copyright. All rights are reserved, whether the whole or part of the material is

concerned, speciﬁcally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting,

reproduction on microﬁlm or in any other way, and storage in data banks. Duplication of this publication

or parts thereof is permitted only under the provisions of the German Copyright Law of September 9,

1965, in its current version, and permission for use must always be obtained from Springer. Violations

are liable to prosecution under the German Copyright Law.

The use of general descriptive names, registered names, trademarks, etc. in this publication does not

imply, even in the absence of a speciﬁc statement, that such names are exempt from the relevant protective

laws and regulations and therefore free for general use.

Typesetting and production: le-tex publishing services oHG, Leipzig, Germany

Cover design: WMXDesign, Heidelberg, Germany

Printed on acid-free paper

987654321

springer.com

Foreword

The invention of the scanning tunneling microscope in 1981

has led to an explosion of a family of instruments called

scanning probe microscopes (SPMs). One of the most pop-

ular instruments in this family is the atomic force microscope

(AFM), which was introduced to the scientiﬁc community in

1986. The application of SPMs has penetrated numerous sci-

ence and engineering ﬁelds. Proliferation of SPMs in science

and technology labs is similar to optical microscopes ﬁfty

years ago. SPMs have even made it into some high school science labs. Evolutionof

nanotechnology has accelerated the use of SPMs and vice versa. The scientiﬁc and

industrial applications include quality control in the semiconductor industry and re-

lated research,molecular biology and chemistry, medical studies, materials science,

and the ﬁeld of information storage systems.

AFMs were developed initially for imaging with atomic or near atomic resolu-

tion. After their invention, they were modiﬁed for tribological studies. AFMs are

now intensively used in this ﬁeld and have lead to the development of the ﬁeld

of nanotribology. Researchers can image single lubricant molecules and their ag-

glomerationandmeasuresurfacetopography,adhesion,friction,wear, lubricantﬁlm

thickness, and mechanical properties all on a micrometer to nanometer scale. SPMs

are also used for nanofabrication and nanomachining. Beyond as an analytical in-

strument, SPMs are being developed as industrial tools such as for data storage.

With the advent of more powerful computers, atomic-scale simulations have

been conducted of tribological phenomena. Simulations have been able to predict

the observed phenomena. Development of the ﬁeld of nanotribology and nanome-

chanicshas attractednumerousphysicistsand chemists. Iam veryexcitedthat SPMs

have had such an immense impact on the ﬁeld of tribology.

I congratulate Professor Bharat Bhushan in helping to develop this ﬁeld of nan-

otribology and nanomechanics. Professor Bhushan has harnessed his own knowl-

edge and experience, gained in several industries and universities, and has assem-

VI Foreword

bled a large number of internationally recognized authors. The authors come from

both academia and industry.

Professor Bharat Bhushan’s comprehensive book is intended to serve both as

a textbook for university courses as well as a reference for researchers. It is a timely

addition to the literature on nanotribology and nanomechanics, which I anticipate

will stimulate further interest in this important new ﬁeld. I expect that it will be well

received by the international scientiﬁc community.

IBM Research Division Prof. Dr. Gerd Binnig

Rueschlikon, Switzerland

Nobel Laureate Physics, 1986

Preface

Tribology is the science and technology of interacting surfaces in relative motion

and of related subjects and practices. The nature and consequences of the interac-

tions that take place at the moving interface control its friction, wear and lubrication

behavior. Understanding the nature of these interactions and solving the technolog-

ical problems associated with the interfacial phenomena constitute the essence of

tribology. The importance of friction and wear control cannot be overemphasized

for economic reasons and long-term reliability.

The recent emergence and proliferation of proximal probes, in particular tip-

based microscopiesand the surfaceforce apparatusand of computationaltechniques

for simulating tip-surface interactions and interfacial properties, has allowed sys-

tematic investigations of interfacial problems with high resolution as well as ways

and means for modifying and manipulating nanostructures. These advances pro-

vide the impetus for research aimed at developing a fundamental understanding of

the nature and consequences of the interactions between materials on the atomic

scale, and they guide the rational design of material for technological applications.

In short, they have led to the appearance of the new ﬁeld of nanotribology and

nanomechanics.

The ﬁeld of tribology is truly interdisciplinary. Until 1980s, it had been dom-

inated by mechanical and chemical engineers who conduct macro tests to predict

friction and wear lives in machine components and devise new lubricants to min-

imize friction and wear. Development of the ﬁeld of nanotribology has attracted

many more physicists, chemists, and material scientists who have signiﬁcantly con-

tributed to the fundamental understanding of friction and wear processes and lubri-

cation on an atomic scale. Thus, tribology and mechanics are now studied by both

engineers and scientists. The nanotribology and nanomechanics ﬁelds are growing

rapidly and it has become fashionable to call oneself a “tribologist.” The tip-based

microscopies have also been used for materials characterization as well as for meas-

urement of mechanical and electrical properties all on nanoscale. Since 1991, inter-

national conferences and courses have been organized on this new ﬁeld of nanotri-

bology, nanomechanics, and nanomaterials characterization.

VIII Preface

There are also new applications which require detailed understanding of the

tribological and mechanics processes on macro- to nanoscales. Since early 1980s,

tribology of magnetic storage systems (rigid disk drives, ﬂexible disk drives, and

tape drives) has become one of the important parts of tribology. Microelectrome-

chanical Systems (MEMS)/Nanoelectromechanical Systems (NEMS) and biode-

vices, all part of nanotechnology, have appeared in the marketplace in the 1990s

which present new tribological challenges. Another emerging area of importance

is biomimetics. It involves taking ideas from nature and implementing them in an

application. Examples include Lotus eﬀect and gecko adhesion. Tribology of pro-

cessing systems such as copiers, printers, scanners, and cameras is important al-

though it has not received much attention. Along with the new industrial applica-

tions, there has been development of new materials, coatings and treatments such

as synthetic diamond, diamondlike carbon ﬁlms, self assembled monolayers, and

chemically grafted ﬁlms, to name a few with nanoscale thicknesses.

It is clear that the general ﬁeld of tribology has grown rapidly in the last thirty

years. Conventional tribology is well established but nanotribology and nanome-

chanics are evolving rapidly and have taken the center stage. New materials are

ﬁnding use. Furthermore, new industrial applications continue to evolve with their

unique challenges.

Very few tribology handbooks exist and these are dated. They have focused on

conventionaltribology, traditional materialsand matured industrialapplications.No

mechanicshandbook exists. Nanotribology,nanomechanics,and nanomaterialchar-

acterizationare becomingimportantinmanynanotechnologyapplications.A primer

to nanotribology, nanomechanics, and nanomaterial characterization is needed. The

purposeofthis bookis topresentthe principlesof nanotribologyandnanomechanics

and applications to various applications. The appeal of the subject book is expected

to be broad.

The chaptersin the book havebeen written by internationallyrecognizedexperts

in the ﬁeld, from academia,national research labs and industry,and from all overthe

world. The book integrates the knowledge of the ﬁeld from mechanics and materi-

als science points of view. In each chapter, we start with macroconcepts leading to

microconcepts. We assume that the reader is not expert in the ﬁeld of nanotribol-

ogy and nanomechanics, but has some knowledge of macrotribology/mechanics.It

coversvarious measurementtechniques and their applications, and theoretical mod-

eling of interfaces. Organization of the book is straightforward. The ﬁrst part of the

bookcovers fundamentalexperimentaland theoreticalstudies.The latter part covers

applications.

The book is intended for three types of readers: graduate students of nanotrib-

ology/nanomechanics/nanotechnology, research workers who are active or intend

to become active in this ﬁeld, and practicing engineers who have encountered a tri-

bologyand mechanicsproblem and hopeto solveit as expeditiouslyas possible.The

book should serve as an excellent text for one or two semester graduate courses in

scanning probe microscopy/applied scanning probe methods, nanotribology/nano-

Preface IX

mechanics/nanotechnology in mechanical engineering, materials science, or ap-

plied physics.

I would like to thank the authors for their excellent contributions in a timely

manner. And I wish to thank my wife, Sudha, my son, Ankur, and my daughter,

Noopur, who have been very forbearing during the preparation of this book.

Powell, Ohio Bharat Bhushan

Oct. 16, 2007

Contents

1 Introduction –

Measurement Techniques and Applications

Bharat Bhushan ................................................... 1

1.1 Deﬁnition and History of Tribology ............................. 1

1.2 Industrial Signiﬁcance of Tribology ............................. 3

1.3 Origins and Signiﬁcance of Micro/Nanotribology................. 4

1.4 MeasurementTechniques...................................... 6

1.4.1 ScanningProbeMicroscopy............................. 6

1.4.2 SurfaceForceApparatus(SFA) .......................... 13

1.4.3 VibrationIsolation..................................... 23

1.5 Magnetic Storage Devices and MEMS/NEMS.................... 23

1.5.1 MagneticStorageDevices............................... 23

1.5.2 MEMS/NEMS........................................ 27

1.6 Role of Micro/Nanotribology and Micro/Nanomechanics

in Magnetic Storage Devices and MEMS/NEMS.................. 30

1.7 OrganizationoftheBook...................................... 31

References....................................................... 31

Part I Scanning Probe Microscopy

2 Scanning Probe Microscopy – Principle of Operation,

Instrumentation, and Probes

Bharat Bhushan, Othmar Marti...................................... 37

2.1 Introduction . ................................................ 37

2.2 Scanning Tunneling Microscope . . . ............................. 39

2.2.1 TheSTMDesignofBinnigetal. ......................... 41

2.2.2 CommercialSTMs..................................... 42

2.2.3 STMProbeConstruction................................ 45

2.3 AtomicForceMicroscope ..................................... 46

2.3.1 TheAFMDesignofBinnigetal.......................... 50