3d printing

NTU Singapore and Caltech Designs Stiffness-shifting Chain Mail

Nanyang Technological School (Singapore) and California Institute of Technology (US) have lately published a paper in Nature, describing research into a fresh string mail-like “smart textile” that changes stiffness when compressed.

The string email itself is branded with Nylon, and each string hyperlink is in the form associated with an octahedron, as you can see below. The hollowness of the machine debris allows low density yet high tensile stiffness from the overall fabric.

Octagonal items make the complete (Image credit: NTU Singapore)

The average person “unit allergens” are topologically interlocked, and therefore they are associated like chain email, constraining the machine particles to create the shape of a continuous loose textile. The paper does indeed declare that the textile is more like a 2 dimensional framework overall, despite the definitely 3 dimensional device particles. The string email specimens were branded in single parts, prepared to function.

To regulate the stiffness, the researchers placed the chain email into a transparent plastic again, and removed air from the tote using vacuum. This effectively compressed the unit particles together, causing the unit allergens to jam along, restricting the activity of each particle, and for that reason increasing the stiffness of the overall fabric structure. Actually the mechanism by which these debris lock together is named “jamming transition”, because they jam alongside one another, see?

The pressure increases the packing density of the textile, causing each particle to have significantly more contact with its neighbours, resulting, for the octahedron-based textile, in a composition that is 25 times more rigid.

When produced into a flat, table-shaped composition and vacuum-locked in place, the textile could hold lots of just one 1.5kgs, more than 50 times the fabric’ own weight.

The type of the octahedrons also means that the structure can lock into non-planar shapes as well, like this bridge condition…

Bridge condition carrying lots (Image credit: Caltech)

In another test, the researchers fell a small, 30 gram material ball onto the chain email. The impact deformed the fabric by up to 26 mm when it was laid back, but by only 3 mm when it was stiffened, a six times reduction in penetration depth.

Testing the impact resistance of the materials when unjammed (tender). (Image credit: Caltech)
Evaluating the impact level of resistance of the materials when jammed (rigid). (Image credit: Caltech)

“We wanted to make materials that can transform stiffness on order. We’d prefer to create a textile that moves from tender and foldable to rigid and load-bearing in a controllable way.” said Teacher Chiara Daraio, Professor of Mechanical Anatomist and Applied Physics at Caltech.

You can view a video tutorial of the string mail in action in the training video below.

“With an made textile that is light in weight and tuneable – easily changeable from very soft to rigid – we can use it to address the needs of patients and the ageing society, for instance, to produce exoskeletons that will help them stand, carry loads and assist them with their daily responsibilities,” said Asst. Prof Yifan Wang from the NTU Singapore University of Mechanical and Aerospace Executive,

“Encouraged by ancient string email armour, we used clear plastic hollow debris that are interlocked to enhance our tuneable textiles’ stiffness,” Asst. Prof Wang from NTU’s School of Mechanical and Aerospace Anatomist

“To help expand raise the material’s stiffness and durability, we are actually working on fabric created from various metals including aluminium, which could be used for larger-scale professional applications requiring higher fill capacity, such as bridges or structures.”

You can see a picture of one of the metal samples in the image below.

Stiffness-shifting material email (Image credit: Caltech)

In future, the Caltech / NTU Singapore team is designed to branch out into other materials, as well as research new (non-vacuum assisted) method of handling the rigidity of the textile structures, such much like magnetism, electricity or temperature.

If you’d like to learn about the string mail (and maybe even design + print your own), you can access the paper at this hyperlink.