Growing up, I always had short hair. It was barely ever longer than a classic buzz cut. I swam all the way through college, so having shorter hair was just easier since it was always getting exposed to absurd amounts of chlorine. Cue COVID, graduating college and finishing my swim career, and living with some hippies while working in a National Park for the summer, and I decided to let my hair grow out. To my surprise, it grew out insanely curly! As it has grown out, I have discovered an entire new world of hair science. This has led to numerous hours on the internet trying to figure out how to tame a curly mane and investing in new hair products. For this lab, I have decided to examine some pieces of my hair at different stages of my hair care routine to see how products actually change the physical structure of my hair on the microscopic level. I am also going to be determining characteristics of my hair such as porosity.
Each shaft of hair is made up of three main components, as shown in Figure 3. The cuticle is the outermost layer, which is made up of overlapping cells like ’tiles’. Based on factors including genetics, UV exposure, and hair treatments, the cells in the cuticle can be compact, normal, or raised [https://www.lovedbycurls.com/hair-talk/microscope-porosity-hair/]. If the cuticles are too compact, it can be hard for the required moisture to penetrate into the deeper layers. If the cuticles are spread too wide, hair has a hard time retaining any moisture provided. The cuticle also determines hair density, with wider spread cuticles leading to higher porosity hair. Figure 4 shows the different cuticle structures. The most common way to determine hair porosity is the float test, described below.
My typical hair care routine follows a few steps. This is the basic structure after swimming in the morning, when my hair is the driest. The first step is to use a hair cleanser (not as harsh as a shampoo). This is supposed to remove any buildup and clear the scalp and hair. Next, I use a conditioner to supply moisture. After the shower, I use a leave-in conditioner to add even more moisture. Finally, a curl crème is supposed to help “control fizziness and keep curls defined.” I am interested to see any difference after each of these steps in the cuticle structure using my Foldscope.
Dry hair strands will be examined using the foldscope and the phone attachment with a desk lamp as the light source. The portion of strand viewed under the microscope will be in approximately the middle between the root and the end. The following time points will be examined:
- Post swimming
- Post cleanser
- Post conditioner
- Post leave-in conditioner
- Post curl crème
The float test will also be completed to compare those results with microscopy. This test is completed by placing a hair strand in a glass of water (breaking the surface tension) and seeing if the strand floats or sinks. High porosity hair will sink to the bottom very quickly, as low porosity hair will remain on/near the surface.
Results & Discussion
Washing Routine Analysis
The first sample analyzed was hair collected right after swimming. Figure 5 shows these hair strands. In these hairs, the cuticle was clearly visible and the flaky, overlapping pattern could be seen. The texture on the hair strand appeared overall rough and grainy. Holding the Foldscope at an angle to the light source helped to see more of the texture.
Fig. 5a: Hair post-swimming Fig. 5b
Next, hair was collected after using the cleanser. Figure 6 shows a representative of these hair strands. On the strand examined, it does appear that the surface texture is rougher. Perhaps the cleanser strips the hair of any oils on the strand, exposing more of the cuticle ’tiles’. It is hard to tell off of just the few strands viewed if there is any difference, as there is also a large variation between strands at the same step. Overall, the cuticle seems more exposed after using the cleanser, which correlates with its intended purpose.
Then, post-conditioner hair was viewed. Figure 7 shows representatives of this hair. There was a noticeable change on the hair strands after this step. The flaky look of the cuticle was almost covered by a more scaly texture of darker colored blobs. This is possibly from the proteins/vitamins/moisture that the conditioner supplies to the hair. It is interesting to see that this change is still present even after rinsing the conditioner out. Overall, the hair strands looked smoother, with less exposed cuticle layers showing. When preparing the slide for these hairs, two of them ended up crossing each other in an ‘X’, as shown in Figure 8. This is a clear example of the differences in color between two strands of hair from the same person. However, both of them appear noticeably smoother than in earlier steps.
Next, hair was viewed after leave-in conditioner was applied. Figure 9 shows one of these strands. In this step, the cuticle texture is again visible. However, the ’tiles’ appear to be darker, potentially covered by the leave-in conditioner. The ‘cracks’ between cuticle layers is visible as bright lines against the darker background.
Finally, the curl crème was used and hair was collected for viewing. Figure 10 shows a few of these strands. These strands are the smoothest of all the samples. Barely any cuticle texture is visible. There are also no spots or clumps of residue visible; it appears to be evenly distributed across the strand. This final step is possibly the most impactful with the largest change in texture. A further experiment could look at if this step alone would have the same results on hair directly after swimming. These strands also appear darker, which could be just the color of the individual strands or the thicker crème may block some of the light that normally passes through.
Fig. 10a: Hair post-curl crème Fig. 10b
In the float test, my hair immediately sank to the bottom, as shown in Figure 11. This means that my hair likely has a higher porosity (more water was able to penetrate the hair, causing it to sink). This aligns with the microscopic analysis as the untreated hair had rather exposed cuticles.
There were noticeable changes in the cuticle structure on hair, especially after using the cleanser and the curl crème. These changes make sense based on each products intended use (stripping away buildup and smoothing/moisturizing respectively). This experiment was limited in size, so it is possible that these observed changes were just differences in individual hair strands and had nothing to do with the products. One other experiment I would like to try is looking at hair rinsed in hot VS. cold water, as I have heard that cold water helps to close cuticles and lock in moisture.