A 3D printer can make devices entirely from droplets that can be easily redirected or modulated, Chinese scientists show in Nature Chemical Engineering.

Researchers at China’s South East University in Nanjing have developed a platform that can carry out all kinds of processes in liquid droplets. They use a plate filled with rods less than a millimetre thick, between which a 3D printer (or a researcher) can pipette droplets. Such a drop is about 10 µl and stays in place because of the Laplace pressure of the curved liquid surface. If you place droplets next to it, you get a chain or channel of interconnected droplets that can flow, as shown in the supplementary videos.