How Carbon Nanotubes May Strengthen Bionic Muscles

By Wesley Fenlon

The muscle of the human heart is still better than anything we can create in a lab--but by combining carbon nanotubes with cardiac cells, we're getting closer.

There's a bright future ahead for carbon nanotubes--the wonder material seems to offer endless promise in any number of nano-sized implementations, from invisibility to solar power. The implementation that feels more futuristic, though, is inside the human body. Scientists hope to combine carbon nanotubes with cells from the human heart to create bionic muscles--durable and flexible synthetic materials that could be used to repair damaged hearts or take robotics to a new level of sophistication.

MIT's Technology Review reports that professor Ali Khademhosseini has successfully combined carbon nanotubes, living cardiac cells, and a gel engineered from tissue, surpassing previous attempts to grow cardiac cells. It's the carbon nanotubes that are making a difference. Previous experiments to grow cardiac cells in gels and polymers haven't been as conductive or strong as real heart tissue, according to Khademhosseini. Adding carbon nanotubes to the mixture changes things.

"The Cambridge group solves this problem by adding carbon nanotubes to tissue-engineering gels," writes Technology Review. "The result is a squishy gel with a tangle of strong, conductive carbon fibers embedded in it. Khademhosseini seeded cardiac cells on these gels and studied their properties. The bionic tissues were similar in elasticity to rat heart—much more elastic than previous lab-made materials. They also had much better conductivity. And the tissues were better at heart tissue’s main job, beating in synchrony."

There are still major challenges facing synthetic tissue, like beating in time with the human heart when used as a patch for damaged heart material. When used for robotics, the material would benefit from conductivity, something carbon nanotubes are definitely capable of offering. Until the medical industry decides the carbon nanotubes are non-toxic, we don't expect to see them showing up in the human body. But robotics development doesn't face that concern. Who's ready for androids?