Category Chemistry/Nanotechnology

Jan Genzer et al. Sequential Self-folding of Polymer Sheets. Science Advances, March 2017 DOI: 10.1126/sciadv.1602417

Inspired by origami, North Carolina State University researchers have found a way to remotely control the order in which a 2D sheet folds itself into a 3D structure. “The sequence of folding is important in life as well as in technology,” says Genzer, the S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engin

eering at NC State. “On small length scales, sequential folding via molecular machinery enables DNA to pack efficiently into chromosomes and assists proteins to adopt a functional conformation. On large length scales, sequential folding via motors helps solar panels in satellites and space shuttles unfold in space...

This image from a scanning electron microscope shows a cross section of an object printed using cellulose. The inset shows the surface of the object. Credit: Courtesy of the researchers

Thanks to new research at MIT, cellulose may become an abundant material to print with – potentially providing a renewable, biodegradable alternative to the polymers currently used in 3D printing materials. “Cellulose is the most abundant organic polymer in the world,” says MIT postdoc Sebastian Pattinson. “Cellulose and its derivatives are used in pharmaceuticals, medical devices, as food additives, building materials, clothing – all sorts of different areas. And a lot of these kinds of products would benefit from the kind of customization that additive manufacturing [3-D printing] enables.”

Meanwhile, 3D ...

This is an artist’s illustration shows how PNNL’s addition of the chemical lithium hexafluorophosphate to a dual-salt, carbonate solvent-based electrolyte makes rechargeable lithium-metal batteries stable, charge quickly, have a high voltage, and go longer in between charges. Credit: Pacific Northwest National Laboratory

Adding a small amount of lithium hexafluorophosphate to a dual-salt, carbonate solvent-based electrolyte can make rechargeable lithium-metal batteries stable, charge quickly and have a high voltage...

A carbon fiber composite ink extrudes from a customized direct ink writing (DIW) 3D printer, eventually building part of a rocket nozzle.

Lawrence Livermore National Lab researchers have become the first to 3D print aerospace-grade carbon fiber composites, opening the door to greater control and optimization of the lightweight, yet stronger than steel material. The research represents a “significant advance” in the development of micro-extrusion 3D printing techniques for carbon fiber. “The mantra is ‘if you could make everything out of carbon fiber, you would’ – it’s potentially the ultimate material,” explained Jim Lewicki, principal investigator. “It’s been waiting in the wings for years because it’s so difficult to make in complex shapes...