Proteus Technology: New Material Is Strong, Light and Non-Cuttable

&gt; The freefall of grapefruit from 10 m does not damage the pulp[1] because pomelo peel consists of vascular bundles and an open-pored cellular structure with the struts made of parenchymatic cells.<p>I have a Marsh grapefruit tree, fruiting now (southern hemisphere) as it happens, and I note that it produces particularly pithy progeny. (Ignoring for the moment that Pomelo is one of the parents of the modern grapefruit.)<p>I don&#x27;t have a convenient 10 metre drop to test this, and while I have no reason to doubt the veracity of this citation, I&#x27;m now consumed with curiosity why this plant has evolved to have this feature.<p>I expect it&#x27;s quite an expensive adaptation, and given that modern specimens are the result of a lot of cross-breeding over the years to have juicier pulp and a lower ratio of skin&#x2F;pith to pulp (ie. reduced resistance to damage) it presumably was even more expensive in ancestor plants.<p>Standard fruit purpose is to have animals unwittingly propagate the plant -- entice something to eat the fruit, and some time &#x2F; distance later, deposit the seeds in a fertiliser ball. How does protecting the pulp from these kind of damage assist with that -- unless ancestor trees were spectacularly tall, and ancestor consumers fantastically fastidious on fruit quality.<p>[1] <a href="https:&#x2F;&#x2F;doi.org&#x2F;10.1088%2F1748-3190%2F11%2F4%2F045002" rel="nofollow">https:&#x2F;&#x2F;doi.org&#x2F;10.1088%2F1748-3190%2F11%2F4%2F045002</a>

This non-cuttable metal material sounds extremely useful:<p>&gt; &quot;Security applications such as doors or barriers (as protection from forcible entry attacks) are obvious ones. However, our material technology could also be useful for enhancing the cutting resistance of shoe soles or protective clothing. Workers could benefit from non-cuttable elbow pads or forearm guards in environments with industrial tools.&quot;<p>As someone who cares so much about digital security, physical security feels good.

&gt;ceramic spheres encased in a cellular aluminum structure<p>sounds like the modern &quot;ceramic in a metal matrix&quot; tank armor:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Chobham_armour" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Chobham_armour</a><p>&quot;The (pulverised) ceramic also strongly abrades any penetrator. Against lighter projectiles the hardness of the tiles causes a &quot;shatter gap&quot; effect: a higher velocity will, within a certain velocity range (the &quot;gap&quot;), not lead to a deeper penetration but destroy the projectile itself instead.&quot;<p>From the article on the material<p>&quot;Water jets were also found to be ineffective because the curved surfaces of the ceramic spheres widen the jet, which substantially reduces its speed and weakens its cutting capacity.&quot;<p>Not just water jet, the ceramic&#x2F;metal armor withstands even shaped charge jet :<p>&quot;Because the ceramic is so brittle the entrance channel of a shaped charge jet is not smooth—as it would be when penetrating a metal—but ragged, causing extreme asymmetric pressures which disturb the geometry of the jet, on which its penetrative capabilities are critically dependent as its mass is relatively low. This initiates a vicious circle as the disturbed jet causes still greater irregularities in the ceramic, until in the end it is defeated. The newer composites, though tougher, optimise this effect as tiles made with them have a layered internal structure conducive to it, causing &quot;crack deflection&quot;.[2] This mechanism—using the jet&#x27;s own energy against it—has caused the effects of Chobham to be compared to those of reactive armour.&quot;

This could be a revolution in bike locks. Right now compact battery powered cutting tools can remove just about any bike lock quickly and can easily be concealed.

&gt; The blade is gradually eroded, and eventually rendered ineffective as the force and energy of the disc or the drill is turned back on itself, and it is weakened and destroyed by its own attack.<p>What about an angle grinder disc made of this new material?

I feel like it says a lot about the HN audience that the biggest reply chain is about bike locks, of all things.

One may need to use an angle grinder correctly in a video to convince me. The demo where they plunge the angle grinder straight into the material is no different than the effect on hardened steel. Typically you would start at an edge to minimize the contact area of the cut. That&#x27;s why lock shackles are rounded.

My first thought was &quot;New bike lock material&quot;<p>My second was:<p>&quot;New non-cuttable bike lock defeated by ______&quot;<p>{freezing, shock, heat, _ }

I wish there were a way to get a sample of this to the lockpickinglawyer.

&gt; <i>... hardness may not be a fundamental property of a material but rather a composite one including yield strength, work hardening, true tensile strength, modulus of elasticity, and micro properties such as strength of atomic bonds.</i><p>Now that is pretty interesting.<p>It seems they tuned the material to resist the angle grinder, drill and water jet but it would be interesting to see its ballistic resistance.

Link to scientific paper: <a href="https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;s41598-020-65976-0" rel="nofollow">https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;s41598-020-65976-0</a>

Can someone define &quot;cuttable&quot; and &quot;non-cuttable&quot; in this context?

Also submitted here: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=23903596" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=23903596</a>

I can&#x27;t see the improvement of this vs. walls of high end personal safes. They have used mixed material walls for ages, made from some hard small component (e.g. ceramic) embedded in a more flexible mass (hard rubber).<p>Being accepted in SciRep this material has to have some merit but I am unable to see it.<p>Is the structure even scalable to smaller objects? The other comments talking about bike looks did not read the paper it seems.

I&#x27;m not sure &quot;non-cuttable&quot; is the best description, it is cuttable, but it messes the tools<p>&quot;Cutting resistant&quot; might be a better description, and it is an interesting material regardless<p>Sounds like it works for applications where you need something to absorb &quot;stopping&quot; energy but without wearing out (too much)

How about a plasma cutter? I know a plasma cutter will cut through normal silica. (I cut through some steel plate laying right on top of large gravel.) Silicon dioxides melting point is 1700 C, and aluminum oxide is 2100 C, a little higher.

&gt; The cellular structure showed significant deformability, exceeding 20% of engineering strain as expected from previous studies of cellular metals<p>This only talks about the cellular structure, not the overall material structure, but would this mean that the material would start to deform under a heavier strain? Does that mean it would make sense to not use this material alone, but rather with other materials to make a strong product, e.g. a bike lock with this material on the outside of a thin but rigid pure metal core?

<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Thermal_lance" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Thermal_lance</a>

What about cicular saw with diamond blade? You can cut cement, ceramics and granite with it... What about demolition hammer or hammer drill?

Combined with an energy dissipating foam it would make for some interesting ballistic armor. Especially at 15% the density of steel.

They have used a cheap angle grinder disk, what would have happened if they took a proper diamond one?

Interesting. Now this is worthy of a patent.<p>So the material stops the cutting action, by having air sacs inside itself, where the particulate inside would melt from the friction, and cause the cutter blade to jam itself up.

Heard that one before <a href="https:&#x2F;&#x2F;www.dailymotion.com&#x2F;video&#x2F;x2p7a6d" rel="nofollow">https:&#x2F;&#x2F;www.dailymotion.com&#x2F;video&#x2F;x2p7a6d</a>

Neat idea, very similar to concept of running a chain through a pipe to prevent cutting, but in three dimensions. I do wonder what effect freezing would have on it though.

<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Vibranium" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Vibranium</a> !

Porous Aluminum eh? Wonder how well it stands up to gallium, or acetylene, or MAP gas, or a grind wheel instead of a cutoff wheel.

Waiting for this to exist in an Abus lock so my storage unit can stop being broken into my tweakers.

Nothing in there on its electrical properties. Can it be cut using a plasma cutter?

This resists mechanical forces, but what about EDM milling or plasma ?

That’s pretty cool. can it be cut with bolt cutters or such?

So how do you shape&#x2F;use it during manufacturing?

Aluminum. A highly reactive metal prone to rapid decomposition in household drain cleaner. Yeah, this isn&#x27;t going to revolutionize bike locks.

This would be great for bike locks!

Can Proteus be cut by Proteus?

Space elevator?

Physical shields for spacecraft?<p>Bullet proof vests?<p>Ammunition?

Will this work as armor?

In Star Trek, they called it transparent aluminium!

Sounds amazing, but how will we dispose of this? Looks like 760 C is required to form this. I imagine it will need to be heated above this to dispose of.