A new epoxy material is a first-of-its-kind, 3-D printable, stimuli-responsive polymeric material that enable massive reconfigurability in future military platforms, according to a recent paper.

It will have embedded intelligence allowing it to autonomously adapt to its environment without any external control. It is a system of materials to simultaneously provide structure, sensing and response.

Currently, the stimulus this material responds to is temperature, 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 of its easier to control and apply remotely.

Courtesy Texas A&M University

Polymers are made up of repeating units, like links on a chain. For softer polymers, these chains are only lightly connected to each other through crosslinks. The more crosslinks between chains, the more rigid the material becomes. 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 flexibility introduced to the polymer chain allows it to be fine-tuned, in unprecedented ways, to get either the softness of rubber or the strength of load-bearing plastics.

Dr. Bryan Glaz, associate chief scientist for the U.S. Army's Combat Capabilities Development Command's Army Research Laboratory Vehicle Technology Directorate, said much of the previous work on adaptive materials were for materials systems that are either too soft for structural applications or otherwise not suitable for platform development so turning to epoxies, in some ways, is groundbreaking, and marks "a first step along a very long path toward realizing the scientific possibility for deep future platforms."

This research is part of an exploratory research program led by the corporate laboratory to look at new scientific developments that may disrupt current scientific and technological paradigms 30 to 50 years from now. Glaz said exploratory research, like this, has current significant scientific risk and seeks to address numerous open scientific questions about material performance and durability.