MIT and NASA engineers demonstrate a new kind of airplane wing

Kind of like designing a square wheel that can change into a round one?

a reply to: TEOTWAWKIAIFF

What happens with the fuel normally carried in wings?.
Unless new wing if viable is used in conjunction with a new propulsion system.

Credit: NASA

Building Planes from Modular Blocks

These “blocks” fit into a space known as a voxel, shorthand for volumetric pixel. Those voxels come together to create the larger wing, in the same way a digital image is made up of smaller pixels. They work like lightweight Lego bricks, forming structures that are able to be deconstructed and reconstructed easily into new shapes. This makes the design scalable, easier to model and adaptive for different tasks and needs. Even repairs and replacements are simplified, since there are fewer unique pieces that make up the aircraft.

Finding the right materials to make these components is just as essential as their design. By using a process known as injection molding – where unique materials like thermoplastic polymers are heated into a liquid state, injected into a mold, and then cooled to a solid state –the resulting lattice structures are as stiff and strong as more traditional metal structures.

nasa.gov - What is MADCAT?.

Found it on the NASA site under the project name, MADCAT.

What you are seeing is the self-similar polyethylene struts in a single space called a "voxel." It how strong each one of these blocks are in relation to the ones around it that determine wing deformation and spring back as a whole.

The site is a good read on what is happening with their idea. They are going to use carbon fiber. The wing as computer assisted in creating the proper shape (so they say, but the MIT article says that they don't need to, so not certain which is more correcterer). They go on to explain that sensors are in the wing sending real time air flow data which the computer feeds back to help shape the wing.

There seems to be two version covered by this page and it would be really helpful to differentiate them so we would know something like, "Version 1 was made with carbon fiber, the newer version was made with injection mold plastic as a demo..." or so.

Still, it is kind of a strange idea to put all these blocks together to get a mechanical metamaterial!

What a strange rabbit hole!

First, some history. It all starts with computer programming. When displays started to be used, the first idea was to take pictures and show them on the computer screens. But whole pictures with bulky file transfers were a turn off for those 300 baud modems! So the idea became to "scan" images. This resulted in the picture being reduced down to "picture elements" which could be encoded in a compression scheme so you didn't have to wait hours to download a picture.

Pretty soon people realized that the "picture elements", or "pixels", are how display screens work too. A brilliant idea became to address each pixel on the screen, turning it on, then off, or changing colors, in a certain pattern allowed one "play tennis" on floor TVs... animated pixels and Pong was born! Soon animated pixels became a "world of wonders" and soon we were Defenders, or killing rampaging gorillas to save the princess, defeating Space Invaders, etc.

Screen resolution grew smaller, computers faster, graphic cards appeared, and games became more complex. But the pixel was still a drawback because it was an individual item. Groups of pixels were needed to represent "FPS" or "FPS's targets".

People realized that they had the answer at their finger tips all along: computer programming. When programming, you define what a variable is and proscribe certain attributes to that variable. You can make multi-dimensional containers for those variables... ah! They created cubic arrays of pixels and related them to each other to interact with each other as a whole.

Hence, "voxels" were born! A voxel is a 3D representation consisting of an array of similar elements related to each; a pixel for 3D spaces.

A frenzy of activity followed as people began programming and sharing libraries on-line through places like GitHub. Voxels matured, and like pixels before, became more complex, more complete, more mature.

Continued...

a reply to: TEOT

... continued

Then something happened. A lab technology moved from theoretical to realized...

Additive manufacturing (aka, 3D printing).

Armed with a method of describing 3D spaces, the voxel, the same methodology was tried to be applied to 3D printing.

A defining feature of mechanical metamaterials is that their properties are determined by the organization of internal structure instead of the raw fabrication materials. This shift of attention to engineering internal degrees of freedom has coaxed relatively simple materials into exhibiting a wide range of remarkable mechanical properties. For practical applications to be realized, however, this nascent understanding of metamaterial design must be translated into a capacity for engineering large-scale structures with prescribed mechanical functionality. Thus, the challenge is to systematically map desired functionality of large-scale structures backward into a design scheme while using finite parameter domains. Such “inverse design” is often complicated by the deep coupling between large-scale structure and local mechanical function, which limits the available design space. Here, we introduce a design strategy for constructing 1D, 2D, and 3D mechanical metamaterials inspired by modular origami and kirigami. Our approach is to assemble a number of modules into a voxelized large-scale structure, where the module’s design has a greater number of mechanical design parameters than the number of constraints imposed by bulk assembly. This inequality allows each voxel in the bulk structure to be uniquely assigned mechanical properties independent from its ability to connect and deform with its neighbors. In studying specific examples of large-scale metamaterial structures we show that a decoupling of global structure from local mechanical function allows for a variety of mechanically and topologically complex designs.

pnas.org, April 17, 1917 (abstract) - Decoupling local mechanics from large-scale structure in modular metamaterials.

As you can see, this was not such a smooth transfer as they think "inside out" from how structures interact themselves to exhibit entire system structures. You could not just 3D print out metamaterials, you needed to model behaviors first.

So that is what they did!

While that being figured from a structural viewpoint, other people started to think about 2D materials in a 3D world. Voxel meet graphene! Two of the hottest fields collided as graphene was already being computer modeled. We have not even seen what has been thought up but what has been thought up is pretty amazing! (See photo in post)

MIT is a hotspot for voxel research and 3D printing. So it only made sense to apply the given research to a real world task, the airplane wing! Now you know how voxel relate in 3D space to one another to yield an overall structural design from self-similar triangles!

Not to bad of a rabbit-hole! I leaned a bunch of stuff along the way (this is just the over view!) and other things I had been reading about began to make sense.

Research continues! There will probably be more stories of "wonder designs" and mechanical metamaterials.

a reply to: TEOT

Other groups had suggested the possibility of such lightweight structures, but lab experiments so far had failed to match predictions, with some results exhibiting several orders of magnitude less strength than expected. The MIT team decided to solve the mystery by analyzing the material’s behavior down to the level of individual atoms within the structure. They were able to produce a mathematical framework that very closely matches experimental observations.

The new configurations have been made in the lab using a high-resolution, multimaterial 3-D printer. They were mechanically tested for their tensile and compressive properties, and their mechanical response under loading was simulated using the team’s theoretical models. The results from the experiments and simulations matched accurately.

Source (excerpts and pic),
news.mit.edu - Researchers design one of the strongest, lightest materials known.
Sub-caption: "Porous, 3-D forms of graphene developed at MIT can be 10 times as strong as steel but much lighter"

I posted this in Graphene Mega thread a while back. While I knew it was cool science, I did not realize what was being done because it was not really explained. They modeled the structure from individual graphene flakes upward and then designed a 3D structure to use those self-similar graphene molecules to exhibit new 3D behaviors.

While they do not use the term, "voxel", that is what they actually realized in that pink material! A graphene metamaterial using voxel computations!

Like I said, these things are neat but when you wrap your head around where this is all going... the sky's the limit! (Bad pun, I know! But they are also thinking about using these kinds of concepts for space exploration so who knows where "the limit" actually is!)

a reply to: TEOT

Starting back here, we found out what a "voxel"
is. Then this post to which I am replying, says something about "individual atoms" and "3-D printing" which you needed to apply a little imagination.

Well, for those who haven't put it together yet, here is an article and animated GIF that explains the "where this is headed"

MIT.edu, July 12, 2019 - Automated system generates robotic parts for novel tasks.

The animation is of what looks like a post card version of the famous van Gogh self-portrait, except in brown, that is morphed into Edvard Munch's The Scream. So what? You can do a lot with computer graphics... right? Until you realize what you are actually seeing. You are seeing layers of magnetic voxels that when a magnetic field is applied to cause the voxels to twist (they are tiny actuators). What you are seeing is a flat picture (van Gogh) physically morphing into The Scream as the columns of voxels contort!

The actuators are made from a patchwork of three different materials, each with a different light or dark color and a property — such as flexibility and magnetization — that controls the actuator’s angle in response to a control signal. Software first breaks down the actuator design into millions of three-dimensional pixels, or “voxels,” that can each be filled with any of the materials. Then, it runs millions of simulations, filling different voxels with different materials. Eventually, it lands on the optimal placement of each material in each voxel to generate two different images at two different angles. A custom 3-D printer then fabricates the actuator by dropping the right material into the right voxel, layer by layer.

The whole thing is automated! It takes "a couple to several hours" to run on the computer before finalization and fabrication (same source).

[N]ew 3-D-printing techniques can now use multiple materials to create one product. That means the design’s dimensionality becomes incredibly high. “What you’re left with is what’s called a ‘combinatorial explosion,’ where you essentially have so many combinations of materials and properties that you don’t have a chance to evaluate every combination to create an optimal structure,” Sundaram says.

In their work, the researchers first customized three polymer materials with specific properties they needed to build their actuators: color, magnetization, and rigidity. In the end, they produced a near-transparent rigid material, an opaque flexible material used as a hinge, and a brown nanoparticle material that responds to a magnetic signal. They plugged all that characterization data into a property library.

The system takes as input grayscale image examples — such as the flat actuator that displays the Van Gogh portrait but tilts at an exact angle to show “The Scream.” It basically executes a complex form of trial and error that’s somewhat like rearranging a Rubik’s Cube, but in this case around 5.5 million voxels are iteratively reconfigured to match an image and meet a measured angle.

Beyond just a neat demo is what Sundaram says next...

The work could be used as a stepping stone for designing larger structures, such as airplane wings, Sundaram says. Researchers, for instance, have similarly started breaking down airplane wings into smaller voxel-like blocks to optimize their designs for weight and lift, and other metrics. “We’re not yet able to print wings or anything on that scale, or with those materials. But I think this is a first step toward that goal”

Hum.

The digital library of desired features is what you really need! You can do weight, rigidity, flexion, and maybe even add in your double negative refraction meta-materials so when you, oh lets say, apply an electric current to it, causes it to go see through!

Just like those Big Black Triangles!

Hey, didn't Dr. Tom McGuire of Lockheed's Compact Fusion Reactor fame come from MIT?? A fusion reactor. Graphene skin that can flex and go all see through. Add in that ion engine (also from MIT!) or a plasma jet engine, and nobody would know your triangle wing from a UFO!

Kind makes one wonder...

Here is a nice long article to read over the Holidays all about what is happening with MIT's Center for Bits and Atoms (CBA), voxels, robotic swarm manufacturing, and some real world companies already interested in this manufacturing technology (in case my techno-babble was too much!)

universetoday.com, Oct. 17, 2019 - An Army of Tiny Robots Could Assemble Huge Structures in Space.

Makes me think of Dyson spheres and space port in Star Trek. I like the idea of manufacturing in place (In situ resource utilization). Have one army of robots tearing apart an asteroid, and anther turning materials into useful elements, and another swarm building them! All based on voxel geometry.

(eggnog)