Carbon is the sixth most abundant element in the cosmos, yet its abundance in the earth's crust does not even make it among the top ten elements on our planet. More chemical compounds of carbon are known than for any other element except for oxygen and hydrogen. It plays a critical role on Earth as the "stuff" that Life is made from. Every living cell, plant or animal contains carbon. Even in its pure, elemental form carbon is very versatile. This module will use elemental carbon to illustrate a number of key concepts. These concepts can also be applied to other materials.
Have you ever wondered why our Sun and its planets are round? It appears that even the atoms, the smallest particles that give identity to a substance, follow similar rules. Are there sets of design rules that Nature follows but hides from under our very noses? Is Nature so economical that it uses the same sets of rules repeatedly over a large range of sizes? The purpose of this module is to introduce students to the ubiquity of the spherical objects in our everyday world and how Nature packs them together "to get things done."
Some microscopic, unicellular members of the Fungi Kingdom can impact our lives every day. These important fungi are commonly called yeasts. There are many different types of yeasts found throughout the world. Yeasts cells are studied in our pursuit to better understand cellular and molecular biology, biochemistry, genetics and many other areas of research. One area of this research includes observing the surface structures of yeast cells using SPM. A unique structure of budding yeasts is the bud scar, formed during cell's unusual cell division. The bud scars and other features of these important fungi can be visualized, measured and analyzed using SPM.
The goal of the engineering module is to prepare/teach students and users how SPM can be used to test and visualize material properties such as hardness. Along the way, several key concepts and objectives will be presented to prepare users before embarking upon their own experiments.
A class of substances collectively known as liquid crystals have currently found many uses in our household electronics and other technical applications (e.g., LCD displays for watches and calculators, battery charge indicator, aquarium thermometers, etc.). These substances exhibit physical properties that are between those found for solids and liquids. Nature has used these substances for eons before humans even found uses for them. Did you know that cholesterol, a substance that we love to hate, is a liquid crystal? Did you know that a slug changes the alignment of the molecules in the mucus secretion to affect the fluid's viscosity, depending on the ground that it is crossing? Learn more about Liquid Crystals in this module.
In the Information Age we can no longer efficiently record our massive streams of data and information on tablets of clay or reams of paper. Floppy disks, zip disks, hard disks, CD-ROMs, DVDs are the order of the day. Ever wonder what the data really look like on the storage media? Most of us probably have these thoughts when we "accidentally" erase our files and think of ways
to retrieve & recover the precious data.
Many living organisms incorporate minerals into their body structures for support and protection. Humans and other invertebrate animals use calcium and phosphorus in their bones. But bones are not the only support and protection structures requiring minerals. Chickens and other birds have eggshells made of calcium carbonate, the same compound in chalk. Other animals that use calcium carbonate to produce protective coverings are coral and molluscs, such as clams, snails and chonches. Another group of organisms that produce hard coverings are diatoms, microscopic, unicellular algae. Seashells, egg shells, coral and chalk are composed of the same compounds, but the properties of each is very different. They also look different macroscopically, but what if their nanostructure is visualized, do they still look different? Using SPM students can visualize the nano-structure of the biominerals, as well as the proteins embedded in the various structures that create biocomposites with unique properties.
We can't help but to come into contact with bacteria everywhere we go. Their habitats range from thermal vents on the bottom of the ocean floor to the surface of your skin and teeth. Many species live symbiotically with a diversity of other micro-organisms in biofilms. Biofilms are important from two perspectives. First, it allows microbes to survive, even in hostile environments. The film concentrates nutrients and provides protection. Interactions between different types of organisms within the film provide chemicals and environment that can be mutually beneficial to them. Secondly, biofilms have a major impact on human health and industry. A microbe can hide out from the immune system because of the biofilm.
Most cells, such as red blood cells, require water to function properly and so live in watery environments. The water quickly moves into the cell by osmosis until, like an overfilled water balloon, the cell pops. Plant cells are protected from bursting, in part because each cell is contained in a cell wall. In fact, the pressure created by the water-filled cell pushing out against the cell wall is what keeps many plants, such as tomatoes, petunias, and Cannabis sativa, upright and rigid. When the water pressure, or osmotic pressure, is removed, the plant wilts. Light microscopy can be used to observe both animal and plant cells and their response to high water concentrations, as well as low water concentration. SPM is a valuable tool to observe the nano-structural differences of cells walls: the images can be analyzed to measure the size of cells and membrane structures, or to predict what function the structures may have.
The human genome has about 3 billion base pairs. If the DNA of a single cell were stretched out, it would be about 2 m long--but it all fits inside the nucleus of the cell! In order for it to be so long, yet fit in so small of an area, DNA must have a very space-conserving structure, such as a crystal. The crystalline structure of DNA can be observed through SPM visualization. Distances between bases and base pairs can be determined. The lengths of genes and chromosomes can be calculated for many different organisms.
The uses of gold are quite widespread because of its chemical inertness and the ease with which pure flat films and single crystal surfaces can be prepared. Gold surfaces can be routinely prepared which have a roughness of less than 20nm over 10?m and contain many atomically flat terraces with sizes from hundreds of nanometers to well above 1?m across. The films we investigate in this module have been prepared by thermally evaporating gold onto a flat mica surface in a high vacuum. This procedure results in flat films with a (111) orientation. The films were annealed in a hydrogen flame just prior to use.
It is essential that a student of science and/or engineering understands the intimate relationship between scale and size, micro/nanoscopic structure and the properties of materials and their function at the macroscopic level. Take a look at the microscopic world through optical, scanning electron and scanning probe microscopes in this module, and learn some astonishing facts about how scale and size affect properties and hence functions of substances in our material world.
The objective of the Biological Structures Module is to inform students about the materials which living organisms synthesize and use to maintain structural support. This module will elucidate the morphological similarities and differences of these materials from the macroscopic level of the unaided eye to the nanometer level of Atomic Force Microscopy (AFM). For example, cellulose and chitin serve the same supportive function, are chemically similar and are assembled into large fibrillar polymers and are virtually indistinguishable at the AFM level. Although these biomaterials are structurally and functionally similar, they are produced by vastly different organisms: chitin is found in the cell walls of fungi and the exoskeletons of arthropods, while cellulose is found in the cell walls of plants. Do the properties that make cellulose and chitin ideal for their role as structural materials apply to other biomaterials such as collagen and bone, and, if so, can these properties be found in synthetic materials such as fiberglass?
Everyday people across the planet use electric lights. Incandescent lights in particular are an intimate part of modern society. This module allows you to explore the fundamental scientific concepts behind the operation, aging and eventual failure of incandescent light bulbs. Particular emphasis is given to a practical introduction to the particle structure of matter. Through a constructive and interactive approach, you can follow, model, and predict the behavior of light bulb filaments at the macroscopic, microscopic and atomic level throughout the life of the bulb. The high-resolution image of the aged filament to the left highlights some of the beautiful and fascinating behavior of filaments as they age. In addition to the particle structure of matter, the module provides you with a constructive and interactive introduction to incandescence, deductive reasoning, modern failure analysis, and the process of invention from an historical perspective.
Have you ever heard the sound of tires peeling out on a gravel road in a Hollywood adventure movie? Such ‘fictional friction’ in movies is important to creating the excitement of the chase, but have you ever thought about the importance of real friction in our daily lives? Friction is both friend and foe. Without friction we could not walk or stand or even crawl, but it also costs countless dollars in wasted energy and expensive wear and tear. If we can understand what gives rise to friction and how to control it we can make it work for us and minimize its harmful effects.
Scanning probe microscopes (SPM) allow microscopists to visualize three-dimensional landscapes of atomic proportions. Materials imaged and measured can be electrical, magnetic, mechanical, and even living biological. The family of scanning probe microscopes has no lenses, but rather a probe that interacts with the sample surface. The type of interaction measured between the probe tip and the sample surface defines the type of scanning probe microscope being used. Since the invention of the first scanning tunneling microscope by Heinrich Rohrer and Gerd Binning in 1981, scanning probe microscopy has enabled a burst of nanotechnology achievements that includes the manipulation and arrangement of individual atoms on a surface. This module introduces the theory and application of these nano-visualization tools.
Many natural and man-made objects exhibit beautiful, lustrous colors that seem to shimmer and change as you're viewing angle changes. We call this phenomenon Iridescence. This module will explore the wonders of iridescence as it is found in nature and in engineered materials.