Atomic Force Microscopy: Opening the Teaching Laboratory to the Nanoworld (original) (raw)

Nanoscience Nanotechnology Concepts For High School Students: The Scanning Probe Microscope

2006 Annual Conference & Exposition Proceedings

While nanoscience and nanotechnology are not typically thought of as topics for the high school classroom, introducing such cutting-edge research provides a means to motivate student interest in science and engineering. The interdisciplinary nature of nanoscience & engineering allows for a wide range of topics including physics, chemistry, biology and mathematics to be taught within the exciting context of cutting-edge research. As part of the National Center for Learning and Teaching (NCLT) in Nanoscale Science and Engineering, Northwestern University is developing and testing concepts in nanoscience and nanotechnology. The nano-concept material (NCM) is based on a series of hands-on activities. The NCM are developed in close collaboration with high school teachers and are field-tested for feasibility. Learning theory is incorporated into the development of the materials with the assistance of education specialists. One set of nano-concept materials is being developed around a key measurement technique in nanoscience, scanning probe microscopy. Scanning probe microscopy is an important measurement technique for nanoscience and engineering, and provides a platform from which to teach basic science concepts such as measurements and forces. We will discuss the "hands-on" activities developed to teach concepts in scanning probe microscopy, as well as an assessment on how the materials fit into high school and middle school science curricula. Initial findings from a prototype design project show that the design project was successful in engaging student interest, and that the macroscopic models and activities were helpful in facilitating student understanding of how a scanning probe microscope works. All of the students were able to successfully build a working atomic force microscope and acquire an image.

An educational model of an atomic force microscope

2010

We have constructed an operational, educational model of an atomic force microscope which employs and highlights the fundamental concepts and principles involved in nanoscale microscopy. The probe, which holds the laser source and the cantilever tip, is mounted on ...

Interactive learning of nanophysics phenomena

2005

This paper describes a new method of teaching and experimenting nanophysics effects using a nanomnipulator. This nano-manipulator is formed by a multi-sensory platform connected to an AFM and/or to virtual nano-scenes produced by a real-time simulator. The first objective of this work is the evaluation of a custom-made nanomanipulator compared to the use of a classical Atomic Force Microscope (AFM) interface. These instruments are used to teach one-dimensional nano-physical phenomenon, the approach-retract (AR) one, to university students at master level. The second objective is to determine the role of each sensorial rendering (force, visual and sound) and their combination, in the understanding process of the AR phenomenon. These two objectives have been evaluated quantitatively and qualitatively by analysing student practical work reports.

Introductory Review, Scanning Tunneling Microscopy (STM) & Atomic Force Microscopy (AFM)

Atomic-scale resolution is needed to study the arrangement of atoms in materials and advance the understanding of properties and behavior they exhibit. Since the seventeenth-century optical microscopes using visible light as illumination source have led our quest to observe microscopic species but the resolution attainable quickly reached physical limits due to the relatively longer wavelength of visible light and deterring hazard of using a wavelength in UV spectrum. After the discovery of wave nature associated with particle bodies, a new channel of thought opened considering much shorter wavelength of particles and their special properties when interacting with the sample under observation. These particles i.e. electrons, neutrons and ions were developed in different techniques and were used as illumination sources. Herein, the development of scanning tunneling microscopy which used electrons to uncover irregularities of the arrangement of atoms in a thin material via the quantum mechanical phenomenon of electron tunneling has become a sensational invention. Atomic Force Microscopy (AFM) is a development over STM which relied on measuring the forces of contact between the sample and a scanning probe which overcomes the earlier technique only allowing conductors or pretreated surfaces for rendering them conducting, to be observed. Since measuring contact forces between materials is a more fundamental approach, that is equally and more sensitive than measuring tunneling current flowing between them, atomic force microscopy has been successfully able to image insulators as well as semiconductors and conductors with atomic resolution, by substituting tunneling current with an atomic contact force sensing arrangement, a delicate cantilever, which can image conductors and insulators alike via mechanical “touch” while running over surface atoms of the sample. Since the sample surface contamination with foreign atoms and humidity can affect the success of AFM, in sophisticated labs, it is done in an ultra-high vacuum environment with the surface adequately cleaned of impurities and prepared for flatness. Maintaining such an assembly is challenging, however, AFM has seen the massive proliferation in hobbyist’s lab as well, in form of ambient condition scanning environment technique and through self-assembled instrumentations. The success of ATM as a cost-effective imaging tool with dramatically increased ease of understanding and use particularly with the much needed assistance of significant computing power in the form of personal computers which offset the computational difficulty of resolving experimental information, which in turn is responsible for physical simplicity of instrument design, and thus its proliferation to numerous labs in universities and technology companies worldwide.

Visualization of atomic structure using AFM: theoretical description

We suggest simple model of image formation in atomic force microscope (AFM) taking into account contact deformations of probe and sample during scanning. The model explains the possibility of AFM visualization of regular atomic or molecular structure when probe-sample contact area is greater than an area per atom or molecule in surface lattice. (This is usually the case when lattice to be studied has subnanometer unit cell parameters and AFM investigations are carried out in air in contact mode). Two special peculiarities of AFM visualization of two-dimensional lattice could be observed under such conditions: 1) the inversion of contrast of AFM images, and 2) visualization of "false atom" under single atomic vacancy of surface studied.

Learning the core ideas of scanning probe microscopy by toy model inquiries

2013

Atomic force microscopy has developed from an atomic level imaging technique to a large family of nanoscientific research setups called scanning probe microscopy. Following this trend, we also need to develop our education from instructions to use the instrument for imaging into an approach of deeper understanding of the science behind the technologies. In this article, we describe our new university level scanning probe microscopy laboratory unit to learn the main scientific principles and applications of the instruments. Three inquiries using toy models were designed to cover the core ideas of scanning probe microscopy. Learning outcomes were analyzed and categorized into levels from the research reports of nine students. We found that practically every student learned atomic force imaging basics: scanning and essential properties of the topography image. One-third of the students showed good understanding in image artifacts and probe calibration, but just one of the students reached the level beyond the topography images to scanning force microscopy and combined force and topography techniques in his report. Also, the connection between scanning probe techniques and human senses was considered an important objective in design of this laboratory unit, although with modest success in learning so far.