Wriggling microtubules help understand coupling of 'active' defects and curvature

Imagine a tiny doughnut-shaped droplet, covered with wriggling worms. The worms are packed so tightly together that they locally line up, forming a nematic liquid crystal similar to those found in flat panel displays. Scientists are now reporting on an examination of such an active nematic — but with flexible filaments and microscopic engines rather than worms.
Wriggling microtubules help understand coupling of 'active' defects and curvature