Engineers have designed soft robots that can heal themselves from damage.
Robot, heal thyself. I’m Bob Hirshon and this is Science Update.
Robots made out of soft, flexible materials are ideal for handling fruits and vegetables, assisting in surgery, and safely interacting with people. But they’re also prone to damage from sharp objects and other hazards. Now, engineers write in the journal Science Robotics that they’ve created soft robots that can heal their own wounds. Vrije University of Brussels graduate student Seppe Terryn says they’re made from a network of flexible polymers that repair themselves with heat.
It’s a little bit like a 3D spiderweb. When heated, the microscopic mobility of the polymers is increased, and it can slowly flow into a cut and seal it. And this allows the robots to hurt themselves but heal afterwards.
Terryn says the next step is build in sensors so the robots know when they’ve been damaged. I’m Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
As the technology for robotics advances, robots are being designed using materials other than rigid materials, like metal and plastic. Soft robotics is a subfield of robotics dealing with building robots from highly compliant materials, similar to those found in organisms. In addition, it draws from the way in which organisms move and adapt to their environment. In contrast to robots built from rigid materials, soft robots allow for increased flexibility and adaptability for accomplishing tasks, as well as improved safety when working around humans. These characteristics allow for its use in minimally invasive surgery and food handling. They play an important role in rehabilitation and prostheses.
One problem researchers have encountered with these soft robots, though, is that they are more susceptible to getting injured from sharp objects and high pressure than more rigid robots. To try to get around this probem, researchers at the Vrije University of Brussels are working on developing robots made out of a rubbery polymer—or an elastomer, an elsatic variety of polymer—that can heal itself.
To test the concept of a self-healing polymer, graduate student Seppe Terryn, led by Bram Vanderborght at the Vrije University of Brussels, built a gripper, a robot hand, and an artificial muscle, all with the ability to self heal. They built these devices out of rubbery polymers that look a bit like jelly and with built-in healing capacity.
Once they had their devices built, they tested them by ripping or cutting them. Then, they exposed the devices to heat of 80 degrees Celsius. The researchers discovered that when the polymer was exposed to this temperature for around 40 minutes, the material was able to heal. After 24 hours at 25 degrees Celsius, the damaged robot's strength and flexibility were also restored.
But why is this material able to heal itself? The rubbery polymer is made of a network of microscopic chains that allow the Diels-Alder reaction to take place (this reaction allows new bonds to be made by the molecules). When the heat is applied, it causes the chains to break, giving the polymer material more mobility on the microscopic level. The mobility allows the molecules to close the gap made by whatever damage it sustained. Then, when the material cools, the initial properties are almost completely regained.
The research team working on these robots hopes to be able to add sensors to the robots that would detect when and where they are injured, then deploy targeted heat to the area to heal it.
Now try and answer these questions:
- What is soft robotics?
- Why are these kinds of robots useful? In what kinds of tasks are these robots used?
- What is one disadvantage of using soft robots?
- How are the researchers at the Vrije University of Brussels trying to fix this disadvantage?
- How is it that the soft robots are able to heal themselves?
- Can you think of other ways to improve upon the design of these robots?
You can listen to the Robotic Materials Science Update to learn more about how robotic materials can be inspired by nature.
You also can check out this Self-Healing Materials Extend Robotic Life Span video from AAAS to learn more about the research being carried out by the scientists at the Vrije University of Brussels.
And there's the A Robot That Heals a Little Like Wolverine from Science Magazine.
This Science Update would be a good way to open up discussion with students about design, invention, and innovation. You could listen to it with your students and use the suggested discussion questions to get them thinking not only about the science involved with the design of these particular robots, but also about what they might do to improve on the design or come up with a design of their own.
You also could tie this Science Update in with several lessons from Science NetLinks that focus on innovation and invention, particularly using biomimicry. These lessons are listed below.
6-8 | Hands-On
Thomas Edison for Kids
6-8 | Audio
Organisms in Motion: Practical Applications of Biological Research
9-12 | Video
9-12 | Hands-On