US Army developing self-healing, shape-shifting drone material

The US Army is pulling inspiration from the popular film ‘Terminator 2’ in designing material capable of shape-shifting and autonomously healing.

Made of polymer, the 3D printable component has a dynamic bond that allows it to go from liquid to solid multiple times.

The new material is also equipped with a unique shape memory behavior, providing users with the ability to be program and trigger it to return to a previous form.

The military group foresees the innovation being used to create morphing unmanned air vehicles and shape-shifting robotic platforms.

The Army has teamed up with researchers at Texas A&M for this project, which aims to be a future platform suitable for air and ground missions.

The team also wants the material to boast ‘the reconfiguration characteristics of the T-1000 character in the Hollywood film, Terminator 2,’ 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.

In the film, the Terminator is made of liquid metal capable of shape shifting, mimicking others and self-healing, which is the inspiration for the new material.

‘We want a system of materials to simultaneously provide structure, sensing and response,’ Gardea continued.

The new material is also equipped with a unique shape memory behavior, providing users with the ability to be program and trigger it to return to a previous form

A new family of materials can be made softer or harder by changing the number of cross-linking molecules, thanks to a discovery by researchers from the US Army

The material was first designed to respond to temperature, which is easier for lab tests, but the team understands applying the stimulus in the real world will not be easy or practical.

Gardea explained that they recently added light-responsive technology, allowing users to control and apply temperatures remotely.

Polymers are made up of repeating units, like links on a chain. 

The team also wants the material to boast ‘the reconfiguration characteristics of the T-1000 character in the Hollywood film, Terminator 2

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.

‘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,’ Gardea said.

The military material is equipped with a certain bond that allows it to shift from liquid to solid and is 3D printable and recycled.

The team has also included a shape memory behavior to the design, that lets users program the material so it can remember past forms and return to that specific shape when triggered.

The military group foresees the innovation being used to create morphing unmanned air vehicles and shape-shifting robotic platforms

Dr. Bryan Glaz, associate chief scientist for the lab’s 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.

Glaz said the research team’s scientific advancement marks ‘a first step along a very long path toward realizing the scientific possibility for deep future platforms.’ 

The research and material is still in the discovery phase, but the team has a 3D printed material that could be added to components of unmanned aerial vehicles or rotocraft.

Gardea said the immediate next steps are to enhance the actuation behavior and healing. 

The researchers also want to introduce multi-responsiveness and have the material respond to stimuli beyond temperature and light.