These 3D-Printed Structures Fold Themselves

3D printing has come a long way in recent years, and it seems like every week a new advancement is being made in the field. One area, however, that is still ripe for breakthroughs is in combining 3D printing and electronics. Some headway has been made in that arena, but the major challenge is that traditional electronic circuit printing techniques need a flat surface, which is the opposite of what we want from 3D printing.

But, what if your object could be flat during production, so that conventional electronic printing techniques could be utilized, and then become three-dimensional afterward? That’s what researchers at MIT have achieved by creating 3D-printable structures that fold themselves after they’re removed from the build plate of the 3D printer. These structures remain flat during the printing process, and then fold into specific three-dimensional shapes when they’re removed.

The principle behind this is similar to that of a bimetallic strip (often used in thermostats), which bends as its temperature changes. This happens because two different metals, with different thermal expansion rates, are joined together. As the temperature rises or falls, one will expand more or less than the other, forcing the strip to bend.

These new “Peel-and-go” 3D-printed objects work in the same manner, except that the expansion and contraction is in the polymers and occurs as soon as they’ve cooled after printing. Using this expansion differential, the researchers were able to print a functioning electronic circuit onto the structure, which then became three-dimensional when it was removed from the build plate. More development is surely going to happen, but the potential for 3D-printed objects that contain electronics is pretty huge.