“Researchers have developed a highly robust material with an extremely low density by constructing a structure using DNA and subsequently coating it in glass.”
“I am a big fan of Iron Man movies, and I have always wondered how to create a better armor for Iron Man. It must be very light for him to fly faster. It must be very strong to protect him from enemies’ attacks. Our new material is five times lighter but four times stronger than steel. So, our glass nanolattices would be much better than any other structural materials to create an improved armor for Iron Man.”
im just glad someone is doing the real research
Always a little annoyed at articles like this; “strength” doesn’t tell me anything. If this is 5x more resistant than steel to deformation, but then shatters catastrophically, that limits its use cases substantially. Likewise, compressive, tensile and shear strength are all different properties, only one of which is referenced at all. Still very cool, and I look forward to seeing how it develops and learning more details about its capabilities (when I have more time I’ll read the paper), but vague terminology like this has a bad habit of making stuff sound way more revolutionary than it actually is. /shurg
You won’t find that level of detail in typical articles, because they are intended for the general public and are intended to be an overview that a layman can comprehend.
However, the paper itself, which the article links to, has more detail including deformation testing.
I told myself I wouldn’t read unrelated papers at work, but here we are. :P Yeah, as expected, the actual paper is way more informative about the structural properties, and about the limitations. (Difficulty fabricating larger samples without voids, said voids resulting in much lower strengths and much less plasticity, uncertain tensile strength, etc.) Fascinatingly though, (at least to me, not having known the details about DNA based metamaterials :P) the details of the properties should be tunable by way of changing the DNA lattice structure. Which makes it a two-part engineering problem, figuring out how to manufacture it at scale, and determining optimal lattice structures for different applications. Definitely exciting, and will be big once we figure these things out.
But that’s not really what I was talking about. While I get that this is an article geared to laymen/the general public, I do think we should be holding science communication to a higher standard. What was discovered is exciting, but we don’t know how it can be used yet, or if it will ever be practical to do so. Overview is fine, I’d just like some more qualifiers and less speculation. Maybe it’s just me, but I feel like some more care would do a lot to improve overall scientific literacy and trust in the scientific community. /shurg
While I get that this is an article geared to laymen/the general public, I do think we should be holding science communication to a higher standard.
I agree with you 100%.
If they are writing using proper materials terminology then strength tells you a lot, since it has a pretty rigorous definition: amount of energy absorbed before failure.
Which, given one of the researchers themselves is quoted talking about its strength, I’m guessing they are even unintentionally being more precise than you’re expecting of them.
As for the properties: smaller sections being stronger is fairly normal amongst materials. The smaller a manufactured section, the more catastrophic any given defect will be. At a certain scale, you will be guaranteed to have either perfect, or already failed, material.
Could probably make pretty good ablative armor for vehicles.
“one fifth the mass” is not the same thing as “five times lighter”
Consider something that weighs half as much. It’s 50% lighter … 0.5 times lighter. Something that weighs 0.2 times as much has 20% of the weight, and is 80% lighter. If it weighed 1% as much, it would be 99% lighter (0.99 times lighter). If it was 100% lighter … it would weigh nothing. Five times lighter would be -4 times the original mass.
We already have accurate and precise ways to describe less mass (albeit leaving aside for the moment the distinction between mass and weight). It’s no harder to say “one fifth” than “five times”, but only one is correctly describing what is going on.
You’re right that we have precise ways to say this, but people like seeing bigger numbers rather than smaller ones, and most people aren’t “precise” about anything.
Consider something that weighs half as much. It’s 50% lighter … 0.5 times lighter.
It’s a relative metric, not an absolute one. And since they’re using the word “lighter” (i.e. less massive) it means that they’re talking about the reciprocal of mass.
I.e. 1/5 the mass = 5 times “lighter”
If something is 50% the mass of something else, you could say the the heavier one is twice as heavy as the light one. Which means that the light one is two times “lighter” than the heavy one.
But I agree with your sentiment, relative comparisons of reciprocals is confusing at the best of times.
It’s not the word “lighter” that’s the issue, it’s the word “less”. If I say something weighs 80% less, … you know how much that is. 100% less, it weighs even less – nothing at all. 500% less (i.e. 5 times less), suddenly it weighs more?
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Glass armor? Nice try, they stole this from Elder Scrolls!
