I work in a lab so I was interested in exploring how some things lying around look like under the foldscope! I chose superhydrophobicity as a theme. For context, a superhydrophobic material contains a surface that causes water droplets resting on it to bead up (with a contact angle greater than 150º). They start out chemically hydrophobic and become “super” when micro/nano sized structures are added. I found an image from wikipedia that illustrates what this means.
I tried using my foldscope to image the surface of a superhydrophobic surface. For this, I used the surface imaging hack where the lens (x140) is directly coupled on the phone’s camera.
I found an article by Wired where a 2043x magnified image of the surface structure of a superhydrophobic leaf (plume poppy) was posted.
Qualitatively the structures look slightly similar although I need to investigate this more in order to determine what I’m actually looking at.
For fun, I also looked at hydrophobic coatings. The image I took looked really similar to how the spores of fungi look under a folscope (from several previous posts on this website) and that’s how I first found out that this power actually comes from the dried spores of the Lycopodium fern!
You can get a really cool thing called a liquid marble when you coat small droplets of water with this powder. In this case, the droplet coated in this power has a large contact angle despite sitting on a regular surface.
Apparently aphids use a special secreted wax to coat their own excrement, honeydew, into a liquid marble in order to prevent the excrement from entrapping themselves.