Engineers from MIT have successfully printed objects that can transform in to sophisticated formations under an applied magnetic field. This was accomplished by altering the magnetic particles in each section of the object to take on a different orientation of spin then other sections using an electromagnet attached to the 3D printers nozzle.
Through creating these separate charge “domains” certain parts of the final object are pushed towards or away from each other by an applied magnetic field given their difference in orientation of spin.
So after the original electromagnet programs the orientation of said domain any subsequent exposure to exogenous magnetism can bend, fold morph, shrink, expand parts and make them move around in pre-designated ways – behaving sort of like a type of non-electrical machine.
The formations successfully tested thus far include
– Smooth rings that wrinkle up
– Long tubes that squeeze shut
– Sheet that folds themselves
– Spider like grabber that can crawl roll jump and snap together fast enough to catch a passing ball
– “Auxetic” structures that rapidly shrink or expand along two direction
– A ring embedded with electrical circuits and red and green LED lights.
Depending on the orientation of an external magnetic field, the ring deforms to light up either red or green, in a programmed manner.
Xuanhe Zhao, the Noyce Career Development Professor in MIT’s Department of Mechanical Engineering and Department of Civil and Environmental Engineering has proposed applying the technology to a new generation of biomedical devices:
“We think in biomedicine this technique will find promising applications,” Zhao says. “For example, we could put a structure around a blood vessel to control the pumping of blood, or use a magnet to guide a device through the GI tract to take images, extract tissue samples, clear a blockage, or deliver certain drugs to a specific location. You can design, simulate, and then just print to achieve various functions.”
They’ve also created a physical model that predicts with a high degree of accuracy how objects will react to magnetism given certain attributes such as the elasticity, pattern of domains in the structure, and the angle/intensity of said magnetic field.
“We have developed a printing platform and a predictive model for others to use. People can design their own structures and domain patterns, validate them with the model, and print them to actuate various functions,” Zhao says. “By programming complex information of structure, domain, and magnetic field, one can even print intelligent machines such as robots.”