|
The new scanning probe microscopies, and especially scanning tunneling microscopy (STM) and atomic force microscopy (AFM), have captured the interest of the science and engineering communities. Since Binnig and Rohrer received the Nobel Prize in Physics for inventing STM (1) and the first commercial instruments became available in 1986, the number of publications in the new field of scanning probe microscopy (SPM) has increased exponentially. This dramatic growth is an indication that scanning probe techniques
are becoming more widely accepted as powerful tools for investigating the structures and properties of materials in chemistry, physics, biology, geology, materials science, and
engineering. Because of its ultrahigh resolution capabilities and options of imaging in vacuum, air, and solution, SPM has become an increasingly popular research method that is
now beginning to emerge as a quality control tool in industry. Since these microscopes are rather inexpensive tabletop instruments and are relatively easy to operate, they are
ideally suited for undergraduate laboratories. These instruments provide students with an unparalleled opportunity to interactively learn about and visualize surfaces and
surface properties at resolutions down to the atomic scale.
Although SPM methods have been largely limited
to professional researchers and graduate students, there is
increasing interest in introducing this technique at the
undergraduate level (2, 3). We have developed the
first multidisciplinary SPM laboratory course for
undergraduate students using research-grade instrumentation to
demonstrate that this field is mature and established enough
to migrate from the graduate to the undergraduate level.
The primary goal of this project is to create a
unique multidisciplinary SPM undergraduate laboratory
course using affordable, state-of-the-art instrumentation. Our
experience is that the incredible potential of this
relatively simple technique, coupled with its high visual impact,
immediately captures and maintains student interest.
The SPM laboratory course is designed to serve as a magnet
to bring together students from different disciplines and
ethnic backgrounds and to help prepare them for the
imminent revolution in nanoscience, engineering, and technology.
The new SPM laboratory is located in the modern Goldwater Center for Science and Engineering
Technology at Arizona State University (ASU). It contains four
SPM workstations, each of which accommodates two
students who work as a team on each experiment. Thus each
laboratory session has a maximum of eight students.
The SPM laboratory course consists of one
50-minute class per week and one four-hour laboratory session.
Laboratory sessions are offered twice per week, so that up to
16 students can enroll per semester. This course is offered
as an elective upper-division undergraduate laboratory in
all science and engineering departments. Classes are taught
by faculty having expertise in the subject area of the
experiment. The class period is used to provide background
information for the laboratory experiments, a broader
perspective of the subject matter, including current and
potential applications, and a forum for discussion and
cooperative learning. The latter activity includes student teams
answering questions posed by the instructor and sharing the
results of their experiments.
The laboratory part of the course is divided into
three major units: Fundamental Principles, Core
Experiments, and Special Projects. The goal of the first unit is to
provide students with a working knowledge of SPM that is
sufficient to perform routine experiments. The objective of
the second is to illustrate several important applications
SPM, while expanding the students' operational capabilities.
The third provides students with the opportunity to
perform short-term research investigations of their choice under
the direction of a research mentor. The principles taught
include instrument operation; surface structure, defects,
modification, and engineering; adsorption and characterization
of materials on surfaces; surface chemical reactions; and
nanofabrication. The laboratory experiments that have been
developed involve surfaces (ideal and real surfaces and
surface modifications and engineering), materials on
surfaces (adsorption and interaction, molecular characterization,
and self-assembly), chemical reactions, and biological
structures. To date, students have completed several projects on a
variety of materials, including thin films,
microelectronics, polymers, long-chain alkanes, particulates,
carotenoids, DNA, and biological cells and plaque.
In summary, the NSF Leadership Projects in
Laboratory Development Program has provided faculty
members from both science and engineering departments at
ASU with the opportunity to develop a unique
multidisciplinary undergraduate laboratory course in SPM: one of the
most revolutionary approaches to investigating the
structures and properties of materials in the last decade. The
simplicity and flexibility of the SPM method, coupled with the
low cost of SPM instrumentation, combine to make the
proposed course not only feasible at ASU but also at other
educational institutions. We hope this course will serve as a
national model for academic institutions interested in
teaching this exciting subject to upper-division
undergraduate students.
|
Citation
