3D printing used to construct smart contact lens

New Scientist : Researchers are finding that 3D printing may be more versatile than previously thought. Michael McAlpine of Princeton University and his colleagues have succeeded in 3D printing contact lenses that contain quantum-dot LEDs. To do so, they had to integrate five different types of materials and print them onto a curvilinear surface. The finished lens is a transparent polymer that contains the nanoscale LEDs along with silver nanoparticle wiring and organic polymers that form electrical circuits. The US Air Force is funding the project, which could have many uses, including the display of in-flight data and, if sensors were incorporated into the design, the monitoring of pilot health and fatigue. More testing is needed to make sure that the materials used—such as the cadmium selenide in the LEDs—will have no adverse effects on the wearer.