have developed a material that can morph from stiff to soft, making its gradient properties potentially useful in medical implants. The research was conducted by professors Stuart Rowan, Justin Fox and Jeffrey Capadona of the macromolecular science and engineering
and biomedical engineering
departments, and Paul Marasco of the Louis Stokes Cleveland Department of Veterans Affairs Medical Center
The inspiration for the new material came from studying the properties of squid beaks. “Squid beaks are a stiff material, but they have to attach to very soft tissue,” explains Rowan. “They don’t have any bones per se. Imagine a piece of steel attached to a piece of plastic and you started bending or putting stressors on it. Things would start to tear, and that’s obviously not very good for the squid.”
Capadona, Marasco and Rowan came up with the idea after reading a research paper
published in 2008 at the University of California, Santa Barbara. Rowan and his team looked at how the squid’s beak transitions from hard to soft material. “How the squid solves the problem is with a gradient design that goes from hard to soft when wet,” explains Rowan. “We created a material with a similar kind of structure. We tried to mimic the architecture and properties.”
The nanocomposite material the researchers developed changes properties when wet -- going from a rigid material to a soft material. It potentially will prove useful in medical devices such as diabetic glucose sensors, prosthetic limbs and central vein ports. The researchers are now working with the Cleveland Department of Veterans Affairs to develop uses for the material.
The research was recently published in the Journal of the American Chemistry Society
Rowan and Capadona previously had studied the properties of the sea cucumber, developing a self-healing polymer that is useful in coating. Rowan enjoys taking his cues from natural phenomena.
“As a materials person, I can learn a lot from seeing how nature has evolved to tackle the challenges that we see in our world, too,” Rowan says. “Nature makes a wonderful variety of very cool materials. The key is in understanding how nature does that.”
Source: Stuart Rowan
Writer: Karin Connelly