Researchers at Purdue University are developing a robotic fabric for use in clothing and “soft” robots. Such technology could be find application in clothing that adds strength and endurance to the wearer or lightweight robots durable enough for planetary exploration in space.
The robotic fabric is a cotton material, fitted with sensors made of a flexible polymer and a shape-memory alloy that changes shape when exposed to heat, causing the fabric to move, functioning similarly to a muscle. The “sensory skin” can be used for gathering feedback data and environmental information.
“We have integrated both actuation and sensing, whereas most robotic fabrics currently in development feature only sensing or other electronic components that utilize conductive thread,” said Rebecca Kramer, an assistant professor of mechanical engineering at Purdue.
The technology could be incorporated into normal clothing at some point, since the creation of the fabric utilizes traditional sewing techniques for incorporating thread-like actuators and sensors into the cloth. This allows for the possibility of integration with existing textile manufacturing.
In a demonstration of the fabric’s function, while wrapped around a block of foam, the robotic fabric caused the block to bend and move, imitating the movement of an inchworm. It can also compress in another fashion, creating a slithering motion.
The research actually comes from work on a NASA Early Career faculty award focused on “active elastic skins for soft robotics,” from Kramer and doctoral students Michelle Yuen, Arun Cherian, Jennifer Case and Justin Seipel. Their findings are detailed in a paper presented at the International Conference on Intelligent Robot and Systems held in mid-September in Chicago.
The goal of the project is to embed flexible electronics into a stretchable skin that’s less sensitive to vibration than ordinary hardware, making it durable enough for missions in space. The idea is that astronauts could easily store sheets of robotic fabric and assemble them when needed.
“We will be able to design robots on the fly,” Kramer said. “Anything can be a robot because all of the robotic technology is in the fabric or skin.”
A related study on “variable stiffness fabric” is detailed a paper authored by visiting graduate student Thomas Chenal from Ecole Polytechnique Fédérale de Lausanne in Switzerland, Purdue doctoral student Jennifer Case, EPFL researcher Jamie Paik, and Kramer.
Changes in heat cause the shape-memory polymer to either stiffen or soften. Applying an electrical current to the polymer causes this “phase transition,” allowing the fabric to soften. It’s actually an energy-efficient process.
“Ordinarily, if we are moving a hinge joint and want to maintain a particular position, we would have to maintain a high energy input to keep the joint from relaxing,” Kramer said. “Here, we could just lock it in place.”
In addition to applications in robotics, this technology could be used for medical braces that lock in support.
The trend right now in the consumer electronic market is “wearables,” but at this point, those are mere fashion accessories. The idea of wearing robotic clothing seems to be a more exciting opportunity for practical use in both science and health.
[Image credit: Purdue University]
By Alfredo Dizon, eParisExtra