Because of a special nanoscale coating, the water structures survive without breaking down into droplets even as the encapsulating fluid changes shape. This new form of 3D printing could give rise to flexible and stretchable liquid electronics, aid chemical synthesis, or serve as a transport and delivery system for nanoscale particles.

The team of researchers led by Tom Russell modified a standard 3D printer so it would inject narrow streams of water directly into a small container filled with silicon oil. The streams of water don't break down into droplets thanks to a special nanoscale surfactant – a substance that reduces surface tension – which separates the water from the surrounding liquid.

The surfactant, a "nanoparticle supersoap," simultaneously disperses gold nanoparticles into the water and binding polymers into the oil. After water is injected, the polymers attach to individual water molecules, forming a soap, vitrifying, and locking the water structures into place even as the surrounding oil changes shape.