Princeton Researchers 3d Printing Bio-Electronic Parts
Researchers at Princeton University have taken an important step toward expanding [3D Printing’s] potential by developing a way to print functioning electronic circuitry out of semiconductors and other materials. They are also refining ways to combine electronics with biocompatible materials and even living tissue, which could pave the way for exotic new implants…
Last year, McAlpine used 3-D-printing to make a “bio-electronic” ear. The ear was made from living cells, with a supportive matrix of gooey hydrogel; it also had conductive ink, made from a suspension of silver nanoparticles, which formed an electrical coil that could receive radio signals.
Since then, McAlpine’s group has been working to expand 3-D printing to semiconducting materials that would allow a printed device to process incoming sounds.
…To broaden the 3-D-printing palette, McAlpine’s group built its own printer; most of the ones on the market today are only designed to print plastic. …They also needed to be able to print at a higher resolution. The bionic ear, for instance, had features on the millimeter scale—and to make LEDs they had to go to the micrometer sale.
To make the LED, the Princeton researchers chose quantum dots—semiconducting nanoparticles that emit very bright light in response to electrical current. They also used two kinds of metal to make electrical leads and contacts for the devices, as well as polymers and a silicone matrix to hold it all together.
One challenge when printing with so many inks is the risk that they will bleed into each other. So the researchers had to make sure to suspend each material in a solvent that would not mix with any of the others.
(via 3-D-Printing Bio-Electronic Parts | MIT Technology Review)