Two research groups have used magnetic fields to tune the texture and strength of materials as they are being printed, allowing the formation of complex 3D structures.

Credit: Nature Commun.

André Studart and his colleagues at the Swiss Federal Institute of Technology in Zurich added magnetic particles at different concentrations to resins of varying viscosities. Applying a low magnetic field during the 3D printing process allowed the team to control the orientation of the particles, and hence the texture, within the printed object. The researchers used their technique to create a composite with an intricate internal spiral staircase (pictured). Their system could be used in robotics to print shape-changing objects that respond to environmental triggers, Studart says.

In a separate paper, Studart's former postdoc, Randall Erb, and his team at Northeastern University in Boston, Massachusetts, used the magnetic technique to improve the mechanical strength of 3D printed objects by controlling crack formation.

Nature Commun. 6, 8643 (2015) ; 8641 (2015)