U.S. Army and Texas A&M University researchers have developed a new material that can autonomously heal in air and under water. The 3-D printable and stimuli-responsive polymeric materials are expected to enable massive reconfigurability in future military platforms, said Dr. Frank Gardea, an aerospace engineer and principal investigator of this work for the U.S. Army’s Combat Capabilities Development Command’s Army Research Laboratory.
The breakthrough opens new opportunities for morphing unmanned air vehicles and robotic platforms. As the research matures, the epoxy material is expected to have the ability for massive reconfigurability and have embedded intelligence allowing it to autonomously adapt to its environment without any external control.
Currently, temperature is the stimulus to which this material responds, which researchers first selected because of its ease of use during laboratory testing. In the real world, applying a temperature stimulus is not as easy or practical so they introduced light-responsiveness because it’s easier to control and apply remotely, Gardea said.
“Most cross-linked materials, especially those that are 3-D printed, tend to have a fixed form, meaning that once you manufacture your part the material cannot be reprocessed or melted,” he said. This new material has a dynamic bond that allows it to go from liquid to solid multiple times, which allows it to be 3-D printed and recycled. In addition, the dynamic bonds introduce a unique shape memory behavior, in which the material can be programmed and triggered to return to a remembered shape.
The researchers’ findings, “A Tailorable Family of Elastomeric-to-Rigid, 3D Printable, Interbonding Polymer Networks,” were published recently in Advanced Functional Materials.