Conductive ink is a great tool in the arsenal of the electronics hobbyist, allowing for circuit tracks to be created freehand on almost any surface - but it's hardly well-suited to professional production. A student project at Cornell University has attempt to take an off-the-shelf pen-based conductive ink and bring it out of the hand-construction market into computer numeric control (CNC) with a circuit printer. A relatively simple combination of pen-based two-axis plotter and a Circuit Scribe conductive ink pen, the project was brought to our attention by Embedded Lab and shows considerable promise for small-scale circuit creation. Although limited to single-layer or large-trace and carefully-aligned double-sided boards and showing some issues with accuracy, the project clearly works - and the students behind it, Connor Archard and Feiran Chen, are hoping it will offer an easy way for hobbyists to print working circuits onto flexible materials for new form factors and wearable projects.
Our final project was to create a rapid prototyping machine for electrical circuits by repurposing an old pen plotter that we fitted with an electrically conductive pen. Our plotter utilized an ATmega 1284P to control the x and y-axis motors, and to raise and lower the pen. We created a web app that allowed a user to draw out circuits quickly.