3D Printing Tiny Complex, Multi-material Devices

3D printers are, at this stage of their march through the Singularity, largely confined to printing with only on material, probably due to cost constraints.  But, what if all the materials needed to produce some specialized bit of kit were available in one printer?  Just how complex a device could be manufactured?  Princeton scientists have just manufactured a 2 x 2 x 2 matrix of quantum-dot LEDs as a demonstration of their 3D printer, which can manage five different print materials, including (1) emissive semiconducting inorganic nanoparticles, (2) an elastomeric matrix, (3) organic polymers as charge transport layers, (4) solid and liquid metal leads, and (5) a UV-adhesive transparent substrate layer.

That’s right; five.  And complex; here’s the matrix and a picture of a single LED on a suggestively curved substrate.  I think we are meant to be reminded of a contact lens.

Homework: It’s published in NanoLetters, right here.