Printed electronics has been "invented" in the last decade, using special ink and basically normal inkjet printers. This allows the printing of several circuits (including the antenna) having low complexity.
Using printed electronics for more complex circuits is much more problematic.
At Berkeley researchers have decided to take a different path to printed electronics using a 3D printer rather than an inkjet printer. Notice that using 3D printers for printing electronic boards has been shown at CES 2015 and the 3D printing of a few electronic components has already been demonstrated.
However, this is the first time that a full electronic circuits with various kind of components is being 3D printed.
At Berkeley, see photo, they have first demonstrated how it is possible to print resistors, inductors and capacitors. Then they have shown how to print them as assembled component (in the photo an example of a capacitor and an inductor) and now they have demonstrated the creation of a full circuit to sense the quality of milk left in its cartoon in the fridge.
As time goes by the number of bacteria in the milk increases and this degrades the milk. The degradation is affecting the electrical signals that the circuit sends and monitors. Once a certain thresholds is reached it can signal (by a LED or other means) that it might be better to get a new cartoon (see the clip).
Don't expect to print your next cell phone though, not even in the next decade. But do expect to download form the internet some instructions for your 3D printer to fix something at home.
Just now I am searching for a place to buy a 30kOhm resistor to have a LED showing when the bathroom heater is on. I wish I had this 3D printer to print one right away...