Material Excitement

This one's for my kids, specifically the Junior Mad Scientist and the Little Man. Remember how I told you that they are looking for people to specialize in Materials Sciences, and you both looked at me funny? Well, these might help you understand just how cool, and diverse, that field is. Also, there are scholarships and grants for college going begging in this field. So! check it out, and if this whets your curiosity, I'll find more stuff to read and do experiments with. Especially experiments, because hands-on is fun.

You might not think of sugar as being a material to build with. But in this case, it's being used as a coating and it made the underlying structure stronger, as well.

Hong, Hyo-Wan Anh, and their colleagues wanted to make antibacterial films for plastics that would endure conditions in the mouth, which has a hodgepodge of enzymes and varying pH.The films would also need to be safe for oral use and made with easily available materials and simple synthesis methods. They chose to create a multilayer film made of two polysaccharides: chitosan, which is derived from crustacean shells, and carboxymethylcellulose, a common thickener used in food and pharmaceuticals.

They used an approach called layer-by-layer assembly, which consists of electrostatically depositing alternating layers of opposite charge onto a surface. They deposited five layers each of negatively charged carboxymethylcellulose and positively charged chitosan onto sheets of polyethylene terephthalate (PET), the transparent plastic used to make most dental devices. This resulted in a clear, 1.8-µm-thick coating. The carboxyl groups in carboxymethylcellulose and the amine groups in the chitosan are superhydrophilic: They attract water, creating an ultrathin, smooth water film on the plastic surface that keeps bacteria from sticking

This next bit is an advertisement, so it's perhaps a bit overenthusiastic, but it's still a good indicator of what people are working on for vehicles. Keep in mind, the lighter an engine and chassis can be made, the more likely it'll be able to fly... flying cars might be in our future after all!

Jose Chirino, technical director for the High Performance Materials business unit at Lanxess, believes his company offers a solution. “We have been active in the automotive industry for many years, implementing glass-filled, nylon-based polymers to replace metal in structural components,” Chirino says.

For example, Lanxess has developed a high-temperature-stabilized polyamide that can withstand temperatures up to 230 °C. When combined with 35% of glass fibers, the product is ideal for making parts that need to withstand high temperatures, such as intake manifolds. Coatings, strong but light frameworks... how about growing some cushions? Yup, you can do that with fungus. If you follow the link, you can do almost anything with fungi... Little Man, you don't have to eat it. This scientist doesn't like the texture any more than you do!

More recent innovations have moved fungi applications from the reductionist use of individual chemicals to a holistic use of the entire organism. Commercial examples range from small—eco-friendly shipping materials and vegan leather for shoes and purses—to large, with biodegradable fungi insulation and custom-molded furniture.

And of course, the wave of the future use of materials to make things, from engine parts to human organs and beyond is 3D printing. While you've seen it done - and designed projects to be printed! -with hard plastic resin, scientists are working hard on being able to print with liquid.

in fused deposition modeling, a 3D digital computer-aided design (CAD) model is converted into a physical object through layer-by-layer deposition of thermoplastic by melting of a solid filament. After deposition, the plastic rapidly cools and serves as support for the next layer, allowing the object to be built from the bottom up. While conceptually straightforward, success requires specific combinations of materials properties and printing process parameters to meet application criteria [4]. The search for the right parameter combination can become even more complex with new materials and new 3D printing methods. For example, silicone elastomers have emerged as a viable material for applications in wearable sensors and medical devices, yet these polymers are often liquids before crosslinking and face gravity-driven collapse using traditional 3D printing. Recently, our group and others have reported new approaches to soft material 3D printing by depositing material within a sacrificial support bath [5–7]. We have termed this process freeform reversible embedding (FRE) [6]. In FRE the support bath is a yield stress fluid; above its yield stress, such as that applied by the nozzle, the bath fluidizes and allows deposition of the printed material. Then, once the stress is relieved with the passage of the nozzle, the support bath resolidifies into a viscoelastic solid, and holds the print in place. After the printing is complete, the liquid polymer is crosslinked and can then be removed from the bath as a free-standing object.

Far from being boring and obscure, this is a really cool field of study. I think that if you're both still considering engineering, you should look at these links to articles and papers. Also, look up a broom bot. It made me laugh, but it would be a great project later this summer. We could see how Tricksy reacts to a small robot chasing her!