Carbon-fiber epoxy honeycombs
Balsa wood is well known for its lightweight properties as well as its stiffness in relation to its density. Inspired by these characteristics, scientists have created a new composite material with extreme lightweight and stiffness properties that not only meet, but exceed those of balsa wood.
Using a combination of fiber-reinforced epoxy-based thermosetting resins and 3D extrusion printing techniques, material scientists from the Harvard School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have created created a cellular composite material that outperforms not only balsa wood, but also the best 3-D printed polymers available on the market. You can watch this new material being created here.
To date, 3D printing has not been widely seen as an engineering solution for structural applications. But this new material could change that perception. “By moving into new classes of material like epoxies, we open up new avenues for using 3D printing to construct lightweight architectures,” says Jennifer A. Lewis, the principal investigator and Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard SEAS. “Essentially, we are broadening the materials palette for 3D printing.”
“Balsa wood has a cellular architecture that minimizes its weight since most of the space is empty and only the cell walls carry the load. It therefore has a high specific stiffness and strength,”Lewis continues. “We’ve borrowed this design concept and mimicked it in an engineered composite.”
So what are some of the applications for this new composite? Throughout Europe and North America, balsa wood is widely used as a low-tech core material within turbine blades. Balsa wood is however expensive and variations that occur in nature mean that it is not always consistent in terms of its material quality. These carbon-fiber epoxy honeycombs offer a new sandwich construction option that allows for greater precision in the performance of turbine blades.
Other applications could include its use in yachts and automobiles where strong, yet lightweight materials are desired.
Source and more information here: Harvard University