This video shows colloidal beads (bright dots) that have assembled themselves on a liquid droplet to form a 3-D curved crystalline structure. The positive electric charges cause the beads to repel each other, leading them to arrange themselves naturally in a honeycomb pattern with each particle equally distant from six others.
Credit: William Irvine, University of Chicago
This video shows a representation of the hexagonal crystal pattern that naturally occurs when the crystalline structure is formed. But the regular six-sided pattern doesn't fit perfectly around the spherical droplet, so defects also appear. Researchers found that inserting an interstitial particle (black) causes rearrangements to the lattice that allow the defect to "heal."
The stresses caused by the extra particle can be seen in the creation of yellow and red shapes, which indicate particles coordinated with either five or seven others, as opposed to the normal six others.