Chapter 1, Section 2

Chapter 1, Section 2

Materials

The search for new materials continues. Chemists design materials to fit specific needs. Often they find inspiration in nature. In 1948, while hiking through the woods of his native Switzerland, George de Mestral took a close look at the pesky burrs that stuck to his clothing. When he looked at the burrs under magnification, he saw that each burr was covered with many tiny hooks that could latch on to tiny loops in the woven cloth of his clothing. George had a weaver make two cloth tapes. On the surface of one tape were hooks, and on the surface of the other tape were loops that the hooks could fit into, as shown in Figure 1.6. In 1955 George patented the design for his hook-and-loop tapes. These tapes are used as fasteners for items such as shoes and gloves.

Figure 1.6 This is a magnified view of hook-and-loop tape. Color was added to the photo to highlight the structures. Classifying Does the photograph show a macroscopic or a microscopic view of the tape? Explain.

This story illustrates two different ways of looking at the world—the macroscopic view and the microscopic view. The burrs that George de Mestral used as a model for his tapes are small compared to many objects in nature. However, they were large enough for George to see. Burrs belong to the macroscopic world, the world of objects that are large enough to see with the unaided eye. George needed more than his own vision to see the hooks on a burr. The hooks belong to the microscopic world, or the world of objects that can be seen only under magnification.