Scientists from MIT and the University of Southern California 3D printed tiny, and quite beautiful, sculptures out of two different materials that usually expand when heated.

In a study published in the Oct. 21 edition of the journal Physical Review Letters, LLNL engineers, along with scientists from the University of Southern California, MIT, and the University of California, Los Angeles, describe the 3D printing of lightweight metamaterials with negative thermal expansion that can be “tuned” to shrink over a large range of temperatures.

“This is a new version of a printing method we have developed and used in the past. We used it to create a thermomechanical metamaterial that may enable applications not possible before,” said principal investigator Chris Spadaccini, director of LLNL’s Center for Engineered Materials and Manufacturing. “It has thermomechanical properties not achievable in conventional bulk materials.”

In the paper, the researchers demonstrate a bi-material microlattice structure, printed from polymer and a polymer/copper composite material that can flex inward, causing the structure to contract when exposed to heat over a range of tens to hundreds of degrees. Researchers note the study may be the first experimental demonstration showing large tunability of negative thermal expansion (NTE) in three Cartesian directions of microlattice structures.

Read the full article here: http://canadajournal.net/science/scientists-develop-3-d-printed-structure-shrinks-heated-52537-2016/

Heat-induced shrinkage