New Shape-Shifting Material Could Make Next-Generation Medical Implants

Scientists have developed a new shape-shifting material that transforms into any shape at a given time.

To demonstrate this discovery, the researchers created an artificial flower bud made of the same material and programmed it to bloom or change shape at a chosen time. But apart from creating the lab-grown flower bud, the material could also be used in making medical implants that adopt the right shape at controlled rates inside the body.

Scientists have long started developing shape-shifting materials. However, they typically require an external trigger to start changing form, such as a change in light levels, temperature or acidity. In certain situations, external triggers are not permissible or are ineffective, especially inside the human body.

With this, Sergei Sheiko, a materials scientist at the University of North Carolina at Chapel Hill, created a material that has an internal clock, which allows it to transform at a given time. This allows the transformation to be modified and controlled over time.

"This is similar to a coffeemaker or washing machine," Sheiko told Live Science. "You dial the timer and let it run."

The research team started with conventional soft polymer and changed its molecular structure. The shapes the material takes are controlled by two networks of chemical bonds that serve as counteracting forces. One is elastic, which holds the energy that is responsible for the morphing process, and the other can flow, which controls how quickly the material forms into its final shape. By controlling the number, strength and location of these two bonds, the researchers were able to program how the structure unfolds from seconds to hours.

"The general motivation behind this work was to endow synthetic materials with functions and properties of living tissues," Sheiko said.

Biomedical implants created from this material could be programmed to alter their shape after being inserted into the body. The initial shape may need non-invasive to minimally invasive surgery but the final shape could expand on itself to fit an implant's final desired form, the researchers said.

The next step for the researchers would be to explore how to introduce a dormant period before the shape shifting and to accelerate the change at a given time.

The research team published their findings in the journal Nature Communications.