German researchers have a line on 3D printed circuitry, but with a twist. Using silver nanowires and a polymer, they’ve created flexible and transparent circuits. Nanowires in this context are only 20 nanometers long and only a few nanometers thick. The research hopes to print things like LEDs and solar cells.
Of course, nothing is perfect. The material has a sheet resistance as low as 13Ω/sq and the optical transmission was as high as 90%. That sounds good until you remember the sheet resistance of copper foil on a PCB is about 0.0005Ω.
One of the items built was a flexible capacitor. We assume deforming the capacitor would cause a change in its value making it a reasonable sensor.
The creation steps are relatively simple if you have some chemical gear. A hot oil bath and some ethylene glycol will get you started. Also needed are silver nitrate, polyvinylpyrrolidone, and copper chloride, among other things. You also need a resin such as that used in 3D printing.
However, it wasn’t very clear to us exactly how you’d print the material. So 3D printing your transparent cell phone from Thingiverse may be a ways off, after all.
Of course, there are lower-tech ways of 3D printing circuits. We’ve even seen some that are solderless.
Transparent and Flexible Circuits
Source: HackADay
