05 April 2013
Vol 340, Issue 6128

About The Cover

Cover image expansion

COVER A network of picoliter aqueous droplets generated by 3D printing. After printing, the droplet network folded into a hollow sphere (diameter: 0.4 millimeters). In these designed tissue-like materials, adjacent compartments are separated by lipid bilayers and can communicate with each other and the environment. Such printed materials might be used to deliver drugs or, in the long term, to augment failing organs. See page 48. Photo: Gabriel Villar