Molecules that makes up the solid crystals found in nature are generally so tightly packed together that there’s no room for any of them to move.
So despite their strength and durability, solid crystals have generally not been considered for applications in molecular machines, which must have moving parts that can respond to stimuli.
Now, UCLA researchers have formed a crystal out of molecules that resemble gyroscopes with solid frames. Since each molecule has an exterior case surrounding a rotating axis, the crystal has a solid exterior but contains moving parts.
The new crystal, described in the journal Proceedings of the National Academy of Sciences, is the first proof that a single material can be both static and moving, or amphidynamic.
“For the first time, we have a crystalline solid with elements that can move as fast inside the crystal as they would in outer space,” said Miguel García-Garibay, a UCLA professor of chemistry and biochemistry and senior author of the study.
To create repetitive arrays of molecular machines, or smart materials, researchers have often turned to liquid crystals, which are engineered to use in LCD television screens but also are found in nature.