The cost of 3D printing has come down dramatically to the point you can set up a small printer in your home. Those printers only spit out little plastic baubles, though. The cutting edge of 3D printing involves making fully functional circuits, and researchers from the University of Nottingham in the UK have devised a way to print working electronic circuits with UV light.
This version of additive manufacturing is more like an inkjet printer than the molten plastic 3D printers with which you’re probably familiar. The circuits that come out of this newly designed process are fully functional, which means the printer has to put together multiple materials. The circuits are based on a conductive metallic ink along with an insulating polymeric ink. The two are applied in layers a few micrometers thick, which could lead to complex printed circuit applications. For now, the designs produced on the UV printer are fairly simple.
Other teams have used similar “inkjet” printing methods to create simple circuits, but the resulting devices required finishing steps like drying or curing. What sets this one apart is the integrated UV lamp. The silver nanoparticles in the conductive ink are about 50nm in size. The team realized these particles were capable of absorbing UV light in the 380-420nm range with high efficiency. So, the printing process involves blasting the ink with 395nm UV light, which generates heat within the ink. That converts the liquid ink into a solid conductive film, essentially drying it while it’s still in the printer.
The University of Nottingham researchers, led by engineering professor Chris Tuck, say that this approach makes it easier to print circuits with multiple layers because there’s no pre-processing, drying, or other production steps. There’s some talk of building complex circuits that could consist of several hundred layers, each one just a few micrometers thick. As you can see in the video above, the team managed to create a simple circuit with around an LED in a single step.
In a more complex proof of concept (above), researchers used their printing technique to print a microcontroller and motors for a small battery-powered car. The team has been approached to use this technique for a number of interesting applications that could lead to real-world uses. Maybe in a few years, you’ll be able to build an electronic device in a few minutes simply by pressing a button.