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Atomic force microscopes (AFMs) are instruments that allow
three-dimensional imaging of surfaces with nanometer resolution. Also
used to determine chemical and mechanical properties of surfaces, they
and their cousins, collectively called scanning probe microscopes, are
the principal enabling technologies in the fields of nanoscience and
engineering. Nanoscience and engineering encompass many different
disciplines, e.g. physics, chemistry, materials science,
electrical engineering, and biology. Their common thread is the mutual
focus
on understanding, designing, and controlling processes and devices at
the
nanoscale.
If you complete this course, you will understand the functional principles of AFMs, be able to run one, and interpret the data that you collect. The course has two main parts. The first half of the term emphasizes instrumentation, the second half interpretation. In general, each fortnight there are three one-hour lectures, one one-hour computer lab, and one two-hour instrument lab. A bachelor's degree in science or engineering is sufficient background. Previous students have indicated that the course was not only helpful to their research, but also in finding employment. You must pass the course in order to use my AFMs in your future research. Auditors are welcome to sit in the lectures. However, they may not partake in the labs due to the high cost of supplies, the limited number of TAs, and licensing issues.
AFM | Grading
| Syllabus | Calendar
| Objectives | Materials
| Prelabs and labs | HW and
presentation | Communication and dates
| Type of Assignment |
# x % (Min.Words) |
Comments |
Pts. |
| PL, prelabs |
6 x 1 % (100) |
REQUIRED, no lab time until PL done to acceptable level |
5 |
| IL, instrument lab reports |
3 x 3 % (300) 2 x 6 % (600) 1 x 12 % (1200) |
REQUIRED, missed lab = -2n % of final grade, where n is the
number of missed labs. Late reports
-1 pt/day, each lab report must be done to an acceptable
level |
20 |
| EX, exams | 2 x 10 % | REQUIRED, missed exam = -1n % of final grade, where n is the
number of missed exams |
50 |
| PP/PA/PR, project proposal, abstract, presentation | 1 %, 4 % (400), 5 % |
late work not accepted. PP and PA must be
done in order to participate in PR. |
5 |
| Lecture |
5 % |
late work not accepted |
5 |
| CL, computer lab reports | 7 x 2 % (200) | late work not accepted |
5 |
| HW, homework | 6 x 2 % (200) | late work not accepted | 20 |
| Rating | 5-pt scale |
| Suggests competence |
2 |
| Demonstrates competence |
3 |
| Suggests mastery |
4 |
| Demonstrates mastery |
5 |
PART I – INSTRUMENTATION
Unit 1, Fundamentals of imaging
PART II – INTERPRETATIONClass 1: IntroductionUnit 2, Difficulties of imaging
Class 2: SPM and AFM instrumentation
IL1: Laboratory procedures
IL2: Acquiring an image
CL1: Image processing
ML1: Static spring constant
Class 3: Feedback and artifactsUnit 3, Other SPMs and operational modes
Class 4: Perturbations and noise
Class 5: Fast fourier transforms
IL3: Optimizing an image and lateral force microscopy
CL2: Feedback and noise
CL3: Fast fourier transforms
ML2: Tip imaging
Class 6: Scanning tunneling microscopyUnit 4, Calibration
Class 7: Lateral force microscopy
Class 8: Operational modes
IL3: Optimizing an image and lateral force microscopy
Class 9: Probe calibrationClass 15: Exam 1 on instrumentation
Class 10: Scanner calibration
IL4: Probe and scanner calibration
ML3: Dynamic spring constant
Unit 5, Force-curve mechanics
Class 11: Potentials, forces, and stiffnesses
Class 12: Force curves
Class 13: Mechanical properties
IL5: Acquiring and processing force curves
CL4: Potentials, forces, and stiffnesses
CL5: Surface forces and cantilever stiffness
ML4: Cantilever instabilities
ML5: Force curve of an infinitely stiff sample
Unit 6, Tip-sample interactions
Class 14: Surface forces
Class 16: Contact mechanics
Class 17: Molecular dynamics
IL6: Contact mechanics
CL6: Contact mechanics
CL7: Molecular dynamics
ML6: Force curve of an unknown sample
Unit 7, A glimpse at current researchClass 18: Student presentations on current researchClass 21: Exam 2 on interpretation
Class 19: Student presentations on current research
Class 20: Student presentations on current research
| Week of | Monday |
Thursday |
Week of |
Monday |
Thursday |
Instrument
Lab OH 009 |
%
this fortnight |
| 9
January |
Introduction -- |
IL1.
Laboratory procedures PL1 |
|||||
| 16 January | MLK Day, no class |
Instrumentation -- |
23
January |
Feedback and artifacts -- |
CL1.
Image processing HW1 |
IL1.
Lab pro IL2. Acquiring PL1,2 |
3 %
|
| 30 January |
Noise and perturbations IL1 Roy, Xu |
FFTs CL1 Lackner, Stanton |
6 February | LFM -- Kaltofen |
CL2. Feedback and
noise HW2 |
IL2. Acquiring IL3. Optimizing, LFM PL2,3 |
8 %
|
| 13 February | STM IL2 Hou, Yao |
Other modes CL2 Burnham |
20 February | Probe calibration -- Cirka, Tao |
CL3.
FFTs HW3 |
IL3. Optimizing, LFM IL4. Calibration PL3,4 |
8 %
|
| 27 February | Scanner calibration IL3 Zeineldin, Yu |
UFk CL3 |
6 MRCH SPRNG BRK! 13 March |
Force curves -- |
CL4. UFk HW4 |
IL4. Calibration IL5. Force curves PL4,5 |
8 %
|
| 20 March | Mechanical properties IL4 |
EX1 CL4 |
27 March | Surface forces PP |
CL5. Stiffness HW5 |
IL5. Force curves IL6. Contact mechanics PL5,6 |
22 %
|
| 3 April | Contact mechanics IL5 |
CL6. Contact
mechanics CL5 |
10 April | Molecular dynamics PA |
CL7.
Molecular dynamics CL6 |
IL6. Contact mechanics PL6 |
15 %
|
| 17 April | Patriot's Day, no class |
Student talks* PR, HW6 |
24 April | Student talks*
PR, IL6 |
Student talks* PR, CL7 |
If unavoidable, make-up labs -- |
21 %
|
| 1 May | EX2 -- |
DDD |
10 %
|
Unit 1, Fundamentals of
imaging (IWGN, IntroNST, IntroAFM, IL1, IL2, CL1, PG Chap.1&5;
SPMLab, UGI Chap.1-3)
1a. Define the
acronyms SPM, SXM, STM, AFM, SFM, LFM, and FFM.
1b. Know in which environments an SPM can operate.
1c. Sketch diagrams showing the difference between
constant-height and constant-strength modes.
1d. State the advantages and disadvantages of AFM and the ways in
which AFM can be used.
1e. Distinguish between the "top-down" and "bottom-up" approaches
to nanotechnology.
1f. Know the effects of the basic image-processing options.
1g. Describe how to acquire and process a contact-mode
constant-normal-force AFM image.
Unit 2, Difficulties of
imaging (PG Chap. 4, DRAFTSects2.2-3, IL3, CL2, CL3; UGI Chap. 4,
FB)
Unit 3, Other SPMs
and
operational
modes (HLI, HLII, PG Ch.1, IL3, STM, FFM; UGII Chs.1&3,
DRAFTChap7)
Unit 4, Calibration
(DRAFTSect4.1, PG Chap.2, IL4, kc_Exercise; StiffCal, UGII Chap. 6)
Unit 5, Force-curve
mechanics (DRAFTChap5, IL5, CL4, CL5, FC_Exercise; MPM, UGII Chap. 4)
| Reading materials |
Lab and homework materials |
| AFM.ShownInLecture,
Things I've been showing you in class AFM.DRAFT, Draft of AFM book FB, Feedback System Response in a Scanning Tunneling Microscope FFM, Friction Force Microscopy HLI, Looking at Atoms HLII, Stroking Molecules IntroAFM, Poster introducing AFM IntroNST, Poster introducing nanoscience and technology IWGN, Nano brochure from IWGN MDI, Molecular Dynamics I MDII, Molecular Dynamics II MPM, Mechanical Properties of Metals PG, A Practical Guide to Scanning Probe Microscopy SFA, Surface Forces and Adhesion StiffCal, Stiffness calibration paper StiffCalII, Another stiffness calibration paper STM, Scanning Tunneling Microscopy |
CLI,
Computer Lab Instructions Data Dlevers.pdf, Data sheet for stiff cantilevers Data Grating, Data sheet for TGTcalibration grating Data MPP31123, Data sheet for compliant cantilevers EXP, Expectations of AFM Users HW3, Homework 3 ICA, I.C.Adams manual * ILI, Instrument Lab Instructions ILR.doc, Template for Instrument Lab Reports (Word) ILR.tex, Template for Instrument Lab Reports (LaTeX) Lab5, Excel file for Lab 5 report Lab6, Excel file for Lab 6 report LP, Laboratory Procedures MLI, Macro-Lab Instructions ML1, Static spring-constant spreadsheet No software for ML2 ML3, Dynamic spring-constant acquisition program ML4, Cantilever-instabilities acquisition program ML5&6, Force-curve acquisition program SPMLab, Manual for V.5.01 * UGI, User's Guide for the M5 Instrument, Part I (Chaps 1-4) * UGII, User's Guide for the M5 Instrument, Part II (Chapter 4) * * The asterix indicates that the document is long and might not be worth printing. |
Between lab reports and prelabs, labs are worth 53 % of your final grade. You will work in teams of two on the instrument, but you will submit individual instrument lab reports. You will work individually on the computer labs and submit individual computer lab reports. All lab reports and prelabs are to be on paper; electronic versions will be accepted with a 20 % penalty. Instrument lab reports should use the template provided in the Study Materials section, and figures should be on separate sheets of paper, stapled to the back of the reports. Find out what to do in the Computer Lab Instructions and Instrument Lab Instructions respectively.
I will answer questions concerning the self-paced computer labs during our regularly scheduled sessions. If you miss a session, your lab report will be expected to be of the same quality as if you had attended. It is also due at the regularly scheduled time. No late reports will be accepted. Any of the almost four-hundred public computers on campus offers the course software. You may also install it on up to two of your own computers, but you are not allowed to distribute it.
The first three instrument labs are for you to learn how to take a good image and are each worth 3 % of your final grade. The fourth concerns calibration, the fifth how to acquire and process a force curve. These are each worth 6 % of your final grade. After learning the basics in the first five labs, the capstone experience is the experiment in the sixth lab where you will take a high-quality image, then acquire and interpret a force curve after calibrating the probe's tip and spring constant. This last lab report is worth 12 % of your final grade. If you have a question about the labs as you write your reports, see me, or talk to the TA. He is Evan Anderson, evan09@wpi.edu, OH 114. Evan will be in the lab, OH 009, on Mondays and Thursdays at 5:00 pm.
You must pass EACH of the six instrument labs
in order to pass the course. If you have an important
appointment
or religious observance that conflicts with your regularly scheduled
lab
session, you may switch lab times with a classmate, but you must inform
me
by email at least a day in advance. If unavoidable, lab make-ups will
be
held the last full week of the term. Missing an instrument lab
session
costs you 2n % of your final grade, where n is the number of missed
times. If you fail to comply
with
the laboratory procedures, you will not be permitted to use the lab;
you will not pass the course. If you were able to perform
the
lab work on time but your lab report is tardy, a one-point penalty per
business
day (out of twenty points) will be enacted. This does not stop at zero!
If,
for example, you fail to turn in Lab 1 on time, and instead wait six
weeks before submitting it, it is worth at most minus ten points.
Instrument labs are
an essential part of the course, and this grading scheme reflects their
importance.
The presentation is a means for you to explore a subject that
interests you. You will synthesize at least six related articles
in cogent fashion for me and the rest of the class. For the
presentation
proposal, bring me hard copies of at least two related publications
that interest
you about modern materials, biophysics, or nanotechnology. One
article
must be from a 2010 or later peer-reviewed journal. (No web sites
unless they are web versions of hard-copy journals. A good place to
start is www.vjnano.org. Let us
define peer-reviewed journals as those
that appear in the Thomson
ISI master journal list, although this definition is more
convenient than accurate.) One article may be older and from a popular
science source, such as Discovery
Magazine
or the New York Times. I want to ensure that the articles are
appropriate
for your talk. (Are they related to the course? Are they specific
enough
to summarize in a few minutes?)
| Homework | Assignment;
see above for key-word links |
| HW1, Fundamentals | 1.
Reading summary of IWGN,
brochure introducing
nanoscience and technology 2. State in kilometers, microns, nanometers, Angstroms, and picometers how far it is from Olin Hall to where you live. 3. Estimate the magnitude of the pressure between a coffee cup and a desk. Write the result with the correct SI unit for pressure. Estimate the magnitude of the pressure between an AFM tip and a sample if the cantilever has a spring constant of 1N/m, it is deflected by ten times the diameter of a hydrogen atom, and the contact area with the sample is a square nanometer. What is the SI prefix for this power of ten? 4. ML1, static spring constant. |
HW2, Difficulties |
1.
Reading summary of
Sects. 2.2-3 on noise and FFTs of the AFM.DRAFT 2. Problem 14, unit analysis 3. Problem 19, obtain Parseval's theorem 4. ML2, tip imaging |
| HW3,
Other SPMs |
HW3 |
| HW4,
Calibration |
1.
Reading summary of Sect. 4.1 on probe
design and calibration of the AFM.DRAFT 2. Problem 29, influence of length of cantilever 3. Scanner sketching exercise. Sketch the equivalent of Figs 2-5, 2-7, 2-10, and 2-11 in PG, not for a square step, but for a square well. There is a small mistake in Fig. 2-7. You should be able to puzzle out the mistake by comparing Figs. 2-6 and 2-7. 4. ML4, cantilever instabilities |
HW5, Force Curves |
1.
Reading summary of Sects.
5.1-2 on force-curve mechanics of
the AFM.DRAFT 2. Problem 48, potentials and equilibrium 3. Problem 56, sliding distance of the cantilever 4. ML5, force curve of an infinitely stiff sample |
| HW6,
Mechanics and Interactions |
1.
Reading summary of Sects. 5.3 and 6.1 on
surface forces of the AFM.DRAFT 2. Problem 63, plane-strain approximation 3. Problem 69, force and potential between polarizable atoms 4. ML6, force curve of an unknown sample |
| Lecture |
The lecture is meant
to give you experience helping students learn a topic, as opposed to
introducing them to a research area, as you will do for your research
presentation. To give you experience with a different medium, try
using the chalkboard. (I anticipate that you will all use computer
slides for your research presentation.) If you feel much more
comfortable with
computer slides, that's fine, but please provide copies of the slides
(two per page) that
students can annotate. I will provide each group of two students
with an outline of the lecture as a starting point. Please feel
free to talk to me about the material ahead of time. |
| PP, Presentation Proposal | For the research presentation proposal, bring me hard copies of at least two related publications that interest you about modern materials, biophysics, or nanotechnology. One article must be from a 2010 or later peer-reviewed journal. (No web sites unless they are web versions of hard-copy journals. A good place to start is www.vjnano.org. Let us define peer-reviewed journals as those that appear in the Thomson ISI master journal list, although this definition is more convenient than accurate.) One article may be older and from a popular science source, such as Discovery Magazine or the New York Times. I want to ensure that the articles are appropriate for your talk. (Are they related to the course? Are they specific enough to summarize in a few minutes?) |
| PA, Presentation Abstract | The presentation abstract will reflect your understanding of the articles. It should be one page, between 400 and 600 words in length, and submitted on paper at the beginning of class on the due date. Refer to the articles (the original two, as well as at least four others) within the abstract and clip all of the articles to the back. The presentation is your verbal capsule thereof, where you will synthesize your articles in a short speech. |
| PR, Presentation | Participation
in the
research presentations, during which you will describe your articles in
a short
verbal presentation, is contingent upon timely submissions of a
presentation
proposal and an abstract. |
| DDD,
Drop-Dead Day |
All
IL and EX work must be submitted
before 8:00 am on 5 May 2011 in order to be included in your final
grade. |