I am a Materials Girl

Category: Academics

Just yesterday I was in my AP Bio class conducting an osmosis lab. Part of this required us to cover the solutions we created with a lid, but our teacher didn’t have enough for each student. As a result she gave us a roll of “tape” and told us to stretch it out. It was way too small to cover the entire mouth of the beaker—it’s safe to say I had my doubts. My partner and I took the tape, stretched it out, and it worked perfectly. In this very moment, I found myself asking: “What material is this?”

Parafilm

Parafilm is a flexible, thermoplastic sealing film made from a blend of polyolefins and paraffin wax. This combination gives it a unique balance of strength, elasticity, and self-adhesion, allowing it to stretch up to twice its length without tearing and form airtight seals around irregular surfaces. In materials terms, Parafilm is valued for its semi-crystalline polymer structure, which provides both flexibility and durability. Its low permeability to water vapor and many gases makes it ideal for preventing evaporation or contamination in laboratory settings. Additionally, it is chemically inert and resistant to mild acids, bases, and aqueous solutions, preserving the integrity of materials it touches. From a materials science perspective, Parafilm is an excellent example of how blending a soft, low-melting component like wax with a tougher polymer matrix can yield a material that combines elasticity, adhesion, and environmental resistance.

References

Gopal, N., et al. “Towards the Development of Flexible Carbon Nanotube–Parafilm Nanocomposites and Their Application as Bioelectrodes.” RSC Advances, vol. 11, no. 54, 2021, pp. 34193–34205, pubs.rsc.org/en/content/articlehtml/2021/ra/d1ra01840j, https://doi.org/10.1039/d1ra01840j.

“Parafilm M.” Agarscientific.com, 2025, www.agarscientific.com/parafilm-174.

I often Google materials science to stay up to date with current research findings and promises of future innovations. There are hundreds of academic papers published every day, with millions published every year. The point is: there is still so much to learn. At my NextEra internship we talked a decent bit about 3D printers and the various types of printers that exist. Plastic, resin, metal, and wax are a few materials that can be printed by a 3D printer. This article titled, “Scientists grow metal instead of 3D printing it — and it’s 20x stronger,” on Science Daily by Ecole Polytechnique Fédérale de Lausanne (EPFL) states there’s an even better alternative. I had already thought 3D printers that create metal were impressive, but to think that there is something better! This is why I love science as a whole: it is always changing and there is no one answer to any problem.

Scientists at EPFL have developed a new way to make metals and ceramics by “growing” them inside 3D-printed hydrogels instead of printing the metals directly. The process involves printing a simple water-based gel, soaking it in metal salts to form nanoparticles, and repeating this several times before heating to remove the gel which leaves behind a dense, high-strength metal structure. This method produces materials up to 20 times stronger and with much less shrinkage than previous techniques. Because the metal is added after printing, the same gel framework can be used to create various materials like iron, copper, or ceramics, offering a cheaper and more versatile approach for building strong, lightweight components for energy, sensor, and biomedical devices. This breakthrough could revolutionize manufacturing by enabling faster, more efficient production of durable materials used in clean energy systems, medical implants, and advanced electronics.

Right now, the new EPFL method is slower than directly 3D-printing metals because it requires multiple soaking and heating steps (called “growth cycles”) to build up metal density. However, it’s more effective in producing stronger, denser, and less warped materials, which means better performance and less waste in the long run. The researchers are currently working on automating the process with robots to make it faster and scalable. So while it’s not more time-efficient yet, it’s material- and quality-efficient, offering a huge advantage for high-precision applications like energy devices or medical implants.

References

Ecole Polytechnique Fédérale de Lausanne. “Scientists grow metal instead of 3D printing it — and it’s 20x stronger.” ScienceDaily. ScienceDaily, 10 October 2025. www.sciencedaily.com/releases/2025/10/251009033209.htm.

I was conducting some research on various materials, and was blown away by this particular material: aerogels. Aerogels are ultralight, porous materials made by removing the liquid from a gel and replacing it with gas/air without collapsing the gel’s solid structure. NASA described it best saying, “Picture preparing a bowl full of a sweet, gelatin dessert. The gelatin powder is mixed with hot water, and then the mixture is cooled in a refrigerator until it sets. It is now a gel. If that wiggly gel were placed in an oven and all of the moisture dried out of it, all that would be left would be a pile of powder. But imagine if the dried gelatin maintained its shape, even after the liquid had been removed. The structure of the gel would remain, but it would be extremely light due to low density. This is precisely how aerogels are made” (NASA).

Aerogels are some of the lightest solids known to mankind. Aerogels are formed by combining a polymer with a solvent to create a gel, then carefully removing the liquid and replacing it with air. The result is an extremely porous, low-density solid that feels firm to the touch. They are often referred to by the nickname “frozen smoke” coming from aerogels’ ghostly appearance and weightless feel. Despite looking fragile, they can support over a thousand times their weight. This translucent material is among the most effective thermal insulators known. These were first invented in the 1930s, however NASA’s Glenn Research Center in Cleveland has invented groundbreaking methods of creating new types of aerogels. NASA has taken aerogels further than anyone imagined, discovering endless possibilities for this incredible material.

References

NASA. “Aerogels: Thinner, Lighter, Stronger – NASA.” NASA, NASA, 28 July 2011, www.nasa.gov/aeronautics/aerogels-thinner-lighter-stronger/.

Two days ago I was on a Zoom call with a university about their Materials Science and Engineering department, and it made me rethink what I knew about the field. The woman associated with the school mentioned the MSE triangle and that any MSE class I will take will guarantee to mention this. I had heard of this triangle before but her discussion made me rethink what I knew about Materials Science and Engineering.

Structure, Processing, and Properties

MSE studies how structure, processing, and properties of materials are related. Structure describes how atoms and molecules are arranged, from the microscopic crystal lattice to larger grain patterns. It determines how strong, flexible, or conductive a material can be. Processing refers to the methods used to shape, treat, or manufacture materials such as heat-treating steel, casting metals, or 3D printing polymers. These processes directly influence the structure, whether by altering grain size, creating new phases, or aligning fibers. Finally, properties are the measurable characteristics we rely on (strength, toughness, conductivity, corrosion resistance) and they emerge from the interplay of structure and processing. The beauty of the triangle is that no corner exists in isolation. Change the processing, and you alter the structure; shift the structure, and you change the properties. This interconnected framework guides scientists and engineers in designing materials for everything.

This year I am a senior in high school and am deep into the college admission process. All of these universities have unique traditions, and one I find very interesting is painting! At Duke, every first-year student leaves their mark by painting the East Campus Bridge during orientation, while at Northwestern, student groups “guard” The Rock for 24 hours before layering on their message. UVA’s Beta Bridge is one of the most visible forums on campus, where paint layers pile up daily with everything from sports cheers to memorials. At Michigan, the Ann Arbor Rock has been repainted so many times since the 1950s that it’s practically a geological formation in its own right.

The bridge painting for Duke is a kick-off activity of Orientation Week for incoming-first year students. (Picture Source: https://today.duke.edu/2012/08/ecampusbridge)
Northwestern undergrads often “guard” the rock for 24 hours to claim the right to paint it next. Picture Source: (https://www.northwestern.edu/about/history/the-rock.html)
UVA’s Beta Bridge often has announcements for campus events, current affairs bulletins, club member recruitments, commemorations of horrific world events, cheers for UVA athletic teams, and so on. (Picture Source: https://discovercharlottesville.com/listings/beta-bridge/)
Michigan’s Rock was originally painted gray, but has since been continuously painted over by students and other members of the community looking to make their (temporary) mark. (Picture Source: https://www.michigandaily.com/news/campus-life/a-campus-tradition-painting-the-rock/)

From a materials science perspective, these traditions are more than just campus fun. Each new coat of paint adds a polymer-based layer, creating a stratified record of pigments, binders, and fillers that interact over time through adhesion, diffusion, and weathering. Environmental exposure (UV radiation, humidity, freeze–thaw cycles) induces degradation, causing chalking, flaking, or microcracking that can expose older layers beneath. The constant repainting also creates a multilayer composite structure, sometimes several inches thick, with mechanical properties similar to laminates: stiff yet brittle, prone to delamination under stress. These campus traditions thus accidently generate living laboratories of applied materials science, where students walking past a rock or bridge are witnessing the durability, failure, and layered complexity of everyday polymers in action.

Here is a close-up of the layers of paint from the Northwestern Rock. (Picture Source: https://evanstonroundtable.com/2021/05/28/northwestern-rock-chipped-and-damaged-for-unconfirmed-reasons/)
These are the layers of paint from the UVA Beta Bridge. (Picture Source: https://news.virginia.edu/content/painting-beta-bridge-tradition-expression)