Looking at Textiles Under the Microscope
Looking at textile fabrics and material under the microscope can be an exciting experiment for students and microscope enthusiasts alike. While fabrics are large enough they can be viewed under a low power stereo microscope, a lot of fine detail can also be observed with the use of the higher power magnification of a compound light microscope. Clothes are made up of a very fine weave of thread, and threads are in turn made up of fibres taken from some plants or animals. The structure of each fibre gives the cloth different textures. For example, run your hands over a wool sweater and compare that with how your T-shirt feels like. Which feels softer? Did fibres stick to your hand when you ran them over the sweater? This is because the sweater and your T-shirt are made up of different fabrics that vary in the way that they are woven. Sounds complicated, doesn’t it? But that just makes it all the more interesting to look at fabrics and thread under the microscope.
Let’s begin with the way threads are woven to make up cloth. Probably you have seen women working at looms in old movies or have read about it in books. The loom is a large, rectangular structure that has a lot of thread stretched out vertically from one edge of the wooden structure to another. These vertical threads are called the warp. To make cloth, other threads would be woven in and out the warp. These horizontal threads are called weft or woof.
Place your handkerchief under a stereo microscope and see how it is woven. There are some variations in the way that cloth is woven to give the fabrics different textures. An example of this would be twills, which have thicker warp and thin weft. Ask an adult to help you identify some of these fabrics in the clothes you have in your closets. You could even cut off samples from the clothes that you have outgrown or the rags you have lying around. Always check on your parents before doing this, though. You don’t want to take samples off from someone’s favourite shirt!
There are other pieces of clothing that you might find interesting to look under the stereo microscope: some clothes and even stockings are made by knitting threads rather than weaving them. Hats and caps are also made from fabrics that are usually ‘felted’ together. Felting is a process where thread is compressed and cemented together to hold a certain shape permanently. You could even examine cloth diapers to see what bird’s eye cloth looks like through the microscope objective lens. Bird’s eye pattern is arranged in a way that there are small eyelike figures that lets air to pass through more easily than in other fabrics.
Now, let’s take one step farther and look at a single thread under a high power microscope. You might want to mount the thread or fibre on a blank microscope slide to be able to see it better under your compound light microscope.
Take some sample threads from the sample that you have cut off earlier. There are usually tags attached to clothes that say what the cloth is made up of. Look for one that is labelled cotton and try looking at its fibres under the compound light microscope. Looking at fibres usually works better using wet mount microscope slides, so be sure to add a drop of water with your sample before covering it with a cover slip.
Cotton fibres look twisted and somewhat flattened under the high power microscope. Try comparing better grades of cotton with normal ones. You could take down notes on how fibres differ in structure too. How do you think this will affect the textures of the fabric? To look at wool under the microscope, take a piece of yarn, which is usually made of virgin wool. Take a sample fibre as you have done with your cotton sample and place your wool slide on the microscope stage. Under the high power objective, you would see that wool fibre seem to be made up of scales like a very small snake. There’s quite a difference since wool comes from sheep hair and cotton comes from plants, isn’t there?
Now try looking at silk fibres. Silk is made naturally from what is spun by silkworms that serves as cocoon covers. Under the high power compound microscope, you would see the reason for the smoothness of silk fabric: silk fibres are shiny and very even.
Another fabric that comes from plants is linen, which begins life as flax. Looking at linen fibre under the microscope would reveal an almost ragged appearance that suggests segments. This structure makes clothes made of linen wear less easily than those made of other fabrics.
There are also clothes made up of synthetic fibres like nylon that look like silk fibres under the microscope. This is because synthetic fibres are made in the same way silk is spun by silkworms. Nylon was first made around the 1930s. What they did was push a liquid form of nylon through tiny holes called spinnerets. Once it passes through the spinnerets and into a hardening acid bath, the liquid solution hardens into nylon fibres.
Examining textiles and even hair (whether human or animal) under the microscope has played important roles in the field of crime-solving and forensics as well. Often hair fibers are compared to each other using the forensic comparison microscope.
The low power stereo microscope is an exciting tool for viewing overall specimens of textile, fabrics, and clothing under the microscope. Overall patterns and designs can be closely examined, including the twists of the fabric. Using the high power compound microscope for single threads, cross sections of threads, or the smallest parts of the fabric can reveal the hidden intricate design. Both types of microscopes are excellent lab tools for the student and teachers alike to examine how things are made.