Magnetic polymers set to be a material of the future
We use magnets almost every day of our lives. They can be found in numerous applications, from fridge door fittings to earphones. These magnets however tend to be made from hard, inflexible metals that are not easily deformable. “This inflexibility limits their application in certain fields,” explains project coordinator Kostas Danas, a senior research scientist at the French National Centre for Scientific Research (CNRS) and associate professor at École Polytechnique in France. “Exploratory medical instruments, for example, where magnetic properties could be useful, need to be highly flexible in order to enter and navigate narrow vessels in the body.”
New class of materials
What if magnetic materials could be made soft and pliable enough to be transformed into complex geometric shapes? This was the objective of the MAGNETO project, funded by the European Research Council (ERC). To achieve this, magnetic materials were broken down into powder, and then mixed with various polymers. The idea was that finalised soft materials could then be manufactured, but this time with magnetic properties. The MAGNETO project was able to achieve a breakthrough in part because of timing. The emergence of advanced 3D printing enabled Danas and his team to attempt much more complex geometric shapes. These first prototypes have opened the door to a whole range of potential new applications, from diagnostic tools to touchscreen displays. In this way, MAGNETO has advanced the development of a new class of materials that did not exist in the 1980s. “We are not the first scientists to attempt this,” Danas notes. “Some early research into these materials was carried out in the late 1990s. But because no successful applications were identified, this research ground to a halt.”
Range of applications
The MAGNETO project has changed all this, even though the materials are so new that they are not yet on the market. Further research and development is still needed. Nonetheless, Danas sees huge potential for this technology, especially in the biomedical industry. “These materials could be used to make biomedical devices such as catheters or drug delivery systems,” he explains. “These are thin and flexible, can enter a vein, and be controlled by an external magnet.” Another possibility is drug delivery. Small magnetic parcels could deliver drugs to exactly where they are needed, again controlled by an external harmless magnetic field. Other high-end applications include tactile – or haptic – devices for blind people. A flat screen would pop up at the touch of a finger, perhaps offering the user a specific menu to select from, without the need for visual consultation. Magnetic polymer materials make this possible. “We are currently 3D-printing materials for this application,” adds Danas. Moving forward, Danas aims to focus on developing ever-more complex geometries, and to improve 3D printing of such materials still further. “Huge developments have been made,” he says. “But we are not quite there yet. Printing 3D magnetoelastic materials is still a challenge, and it can be hard to control the process. This requires more work.” Nonetheless, the project represents an important milestone in the development of this cutting-edge technology. “The results achieved show the benefit of funding fundamental research,” he says. “This ERC grant enabled us to take a risk, to engage in academic research when we did not know what the deliverable would be.”
Keywords
MAGNETO, magnets, medical, polymers, geometric, 3D printing, haptic