Recently there was a bit of a panic in the media regarding a very common item in kitchens all around the world: black plastic utensils used for flipping, scooping and otherwise handling our food while preparing culinary delights. The claim was that the recycled plastic which is used for many of these utensils leak a bad kind of flame-retardant chemical, decabromodiphenyl ether, or BDE-209, at a rate that would bring it dangerously close to the maximum allowed intake limit for humans. Only this claim was incorrect because the researchers who did the original study got their calculation of the intake limit wrong by a factor of ten.
This recent example is emblematic of how simple mistakes can combine with a reluctance to validate conclusions can lead successive consumers down a game of telephone where the original text may already have been wrong, where each node does not validate the provided text, and suddenly everyone knows that using certain kitchen utensils, microwaving dishes or adding that one thing to your food is pretty much guaranteed to kill you.
How does one go about defending oneself from becoming an unwitting factor in creating and propagating misinformation?
Extremophile lifeforms on Earth are capable of rather astounding feats, with the secret behind the extreme radiation resistance of one of them now finally teased out by researchers. As one of the most impressive extremophiles, Deinococcus radiodurans is able to endure ionizing radiation levels thousands of times higher than what would decisively kill a multicellular organism like us humans. The trick is the antioxidant which this bacterium synthesizes from multiple metabolites that combine with manganese. An artificial version of this antioxidant has now been created that replicates the protective effect.
The ternary complex dubbed MDP consists of manganese ions, phosphate and a small peptide, which so far has seen application in creating vaccines for chlamydia. As noted in a 2023 study in Radiation Medicine and Protectionby [Feng Liu] et al. however, the D. radiodurans bacterium has more survival mechanisms than just this antioxidant. Although much of the ionizing radiation is neutralized this way, it can not be fully prevented. This is where the highly effective DNA repair mechanism comes into play, along with a range of other adaptations.
The upshot of this is the synthesis of a very effective and useful antioxidant, but as alluded to in the press releases, just injecting humans with MDP will not instantly give them the same super powers as our D. radiodurans buddy.
Featured image: Survival mechanisms in Deinococcus radiodurans bacterium. (Credit: Feng Liu et al., 2023)
2020 saw the world rocked by widespread turmoil, as a virulent new pathogen started claiming lives around the globe. The COVID-19 pandemic saw a rush on masks, air filtration systems, and hand sanitizer, as terrified populations sought to stave off the deadly virus by any means possible.
Despite the fresh attention given to indoor air quality and airborne disease transmission, there remains one technology that was largely overlooked. It’s the concept of upper-room UV sterilization—a remarkably simple way of tackling biological nastiness in the air.
Researchers have been testing a new type of lithium ion battery that uses single-crystal electrodes. Over several years, they’ve found that the technology could keep 80% of its capacity after 20,000 charge and discharge cycles. For reference, a conventional cell reaches 80% after about 2,400 cycles.
The researchers say that the number of cycles would be equivalent to driving about 8 million kilometers in an electric vehicle. This is within striking distance of having the battery last longer than the other parts of the vehicle. The researchers employed synchrotron x-ray diffraction to study the wear on the electrodes. One interesting result is that after use, the single-crystal electrode showed very little degradation. According to reports, the batteries are already in production and they expect to see them used more often in the near future.
The technology shows promise, too, for other demanding battery applications like grid storage. Of course, better batteries are always welcome, although it is hard to tell which new technologies will catch on and which will be forgotten.
There are many researchers working on making better batteries. Even AI is getting into the act.
The shape of an antenna can make a big difference in its performance. Researchers at the Johns Hopkins Applied Physics Laboratory have used shape memory alloy to construct an antenna that changes shape depending on the signals it is receiving. Nitinol, a common shape memory alloy made from nickel and titanium, is an obvious choice, but it’s not obvious how you’d make a shape-changing antenna out of nitinol wire. That changed when a mechanical engineer found a way to 3D print the substance. You can find a paper about the research online from Applied Engineering Materials.
In practice, the antenna is a double spiral made of nitinol. A channel contains a copper wire that can heat the antenna and, therefore, change its shape. Having a powered wire in the antenna can cause problems, so special designs route the signal away from the heating element. It looks like the antenna can assume a flat configuration or a spiral conic configuration.
A distinct blue pigment reminiscent of turquoise or a clear sky was used by the ancient Maya to paint pottery, sculptures, clothing, murals, jewelry, and even human sacrifices. What makes it so interesting is not only its rich palette — ranging from bright turquoise to a dark greenish blue — but also its remarkable durability. Only a small number of blue pigments were created by ancient civilizations, and even among those Maya blue is unique. The secret of its creation was thought to be lost, until ceramicist and artist [Luis May Ku] rediscovered it.
Maya blue is not just a dye, nor a ground-up mineral like lapis lazuli. It is an unusual and highly durable organic-inorganic hybrid; the result of a complex chemical process that involves two colorants. Here is how it is made: Indigotin is a dye extracted from ch’oj, the Mayan name for a specific indigenous indigo plant. That extract is combined with a very specific type of clay. Heating the mixture in an oven both stabilizes it produces a second colorant: dehydroindigo. Together, this creates Maya blue.
Luis May Ku posing with Maya blue.
The road to rediscovery was not a simple one. While the chemical makeup and particulars of Maya blue had been known for decades, the nuts and bolts of actually making it, not to mention sourcing the correct materials, and determining the correct techniques, was a long road. [May] made progress by piecing together invaluable ancestral knowledge and finally cracked the code after a lot of time and effort and experimentation. He remembers the moment of watching a batch shift in color from a soft blue to a vibrant turquoise, and knew he had finally done it.
Before synthetic blue pigments arrived on the scene after the industrial revolution, blue was rare and highly valuable in Europe. The Spanish exploitation of the New World included controlling Maya blue until synthetic blue colorants arrived on the scene, after which Maya blue faded from common knowledge. [May]’s rediscovered formula marks the first time the world has seen genuine Maya blue made using its original formula and methods in almost two hundred years.
Maya blue is a technological wonder of the ancient world, and its rediscovery demonstrates the resilience and scientific value of ancestral knowledge as well as the ingenuity of those dedicated to reviving lost arts.
The 3D structure of origami-inspired designs comes from mountain and valley fold lines in a flat material. Origami designs classically assume a material of zero thickness. Paper is fine, but as the material gets thicker things get less cooperative. This technique helps avoid such problems.
An example of a load-bearing thick-film structure.
The research focuses on creating so-called “thick-panel origami” that wraps rigid panels in a softer, flexible material like TPU. This creates a soft hinge point between panels that has some compliance and elasticity, shifting the mechanics of the folds away from the panels themselves. These hinge areas can also be biased in different ways, depending on how they are made. For example, putting the material further to one side or the other will mechanically bias that hinge to fold into either a mountain, or a valley.
Thick-panel origami made in this way paves the way towards self-locking structures. The research paper describes several different load-bearing designs made by folding sheets and adding small rigid pieces (which are themselves 3D printed) to act as latches or stoppers. There are plenty of examples, so give them a peek and see if you get any ideas.
We recently saw a breakdown of what does (and doesn’t) stick to what when it comes to 3D printing, which seems worth keeping in mind if one wishes to do some of their own thick-panel experiments. Being able to produce a multi-material object as a single piece highlights the potential for 3D printing to create complex and functional structures that don’t need separate assembly. Especially since printing a flat structure that can transform into a 3D shape is significantly more efficient than printing the finished 3D shape.
