What’s just a bit thicker than a human hair and has ten times the capability of a human muscle? Polymer-coated carbon nanotube yarn. Researchers at the University of Texas at Dallas created this yarn using carbon nanotubes coated with a polymer and coiled with a diameter of about 140 microns.
Passing a voltage through the fiber causes the muscle yarn to expand or contract. Previous similar fibers have to do both actions. That is, they expand and then contract in a bipolar movement. The polymer coating allows for unipolar fibers, critical to using the fibers as artificial muscles.
Continue reading “Nanotube Yarn Makes Strong Bionic Muscles”
Researchers at Rice University are studying 3D printing plastic structures that mimic tubulanes — theoretical nanotube structures predicted to have extraordinary strength. The result has been very strong and very compressible structures that can actually resist bullets.
As an experiment, the researchers fired projectiles at 5.8 km/s at a block of plastic and at a block of simulated tubulanes. The structure of the tubulane block stopped the bullet at the second layer with no significant structural damage beyond the second layer. The reference block had a large hole and cracks throughout its volume.
Continue reading “University Makes Bulletproof 3D Prints”
3D printing has brought the production of plastic parts to the desktops and workshops of makers the world over, primarily through the use of FDM technology. The problem this method is that when squirting layers of hot plastic out to create a part, the subsequent vertical layers don’t adhere particularly well to each other, leading to poor strength and delamination problems. However, carbon nanotubes may hold some promise in solving this issue.
A useful property of carbon nanotubes is that they can be heated with microwave energy. Taking advantage of this, researchers coated PLA filament in a polymer film containing carbon nanotubes. As the layers of the print are laid down, the nanotubes are primarily located at the interface between the vertical layers. By using microwaves to heat the nanotubes, this allows the print to be locally heated at the interface between layers, essentially welding the layers together. As far as results are concerned, the team reports an impressive 275% improvement in fracture strength over traditionally printed parts.
The research paper is freely available, which we always like to see. There’s other methods to improve your print strength, too – you could always try annealing your printed parts.
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[James Tour] and others at Rice University announced an improved form of graphene that uses nanoscale rivets. The material incorporates carbon nanotubes along with carbon spheres that encase iron nanoparticles. The nanotubes provide strength and higher conductivity overall, while the spheres let the material transfer more easily.
Typically, placing graphene on something involves using chemical vapor deposition on a polymer layer before transferring to another site. The polymer tends to degrade the graphene’s properties. This new material doesn’t require this intermediate step. In addition, the spheres allow interfacing to the graphene more readily.
Continue reading “Making Graphene More Practical”