Aiming to provide a quick way to test circuit function on potential products, MIT researchers are 3D printing breadboards into prototypes, including curved prototypes.

The result is ‘CurveBoards’, accurate representations of end-products with breadboard surfaces.

“On breadboards, you prototype the function of a circuit. But you don’t have context of its form – how the electronics will be used in a real-world prototype environment,” said Junyi Zhu of MIT’s Computer science and artificial intelligence laboratory (CSAIL). “Our idea is to fill this gap, and merge form and function testing in very early stage of prototyping an object. CurveBoards essentially add an additional axis to the existing XYZ axes of the object – the function axis.”

While the idea might seem mostly a novelty, the project was a design exercise for a nine person team from CSAIL and MIT’s Department of electrical engineering and computer science (EECS).

They created custom design-editing software that can take a 3D model of the intended shape of the final objects, and automatically map all required pinholes uniformly across it.

Then there is a choice to automatically or manually lay out connectivity channels.

The automatic option offers the user multiple potential layouts, while manual mode offers interactive tools to group holes and select type of connection between them.

Under the hood, according to MIT, the software essentially forces its shape into a “quadmesh” where the object is represented as small squares, each with individual parameters. The holes are cones with the wide end on the surface,  placed at each point where the corners of squares touch. For conductive channel layout, geometric techniques are applied to ensure the chosen channels will connect the desired electrical components without crossing over one another.

Future work includes creating generic templates of common objects such as hats and bracelets, and extending the software to include circuit prototyping – and possibly user interaction – to further hone the design before it is first printed.

Objects are printed from a flexible non-conductive silicone, and the channels behind the holes are filled with a custom conductive silicone designed to from through the channels when injected by syringe.

The team printed CurveBoards for music-streaming headphones with menu controls for the speakers; a heart-rate monitoring interactive bracelet with display, LED, photoresistor and step-counting sensor; a teapot with a camera to track the tea’s colour and coloured LEDs on the handle to indicate hot and cold areas; a flexible wearable e-book reader; watches; frisbees and helmets.

In assessing the utility of their concept, two sections sections were formed to designed similar prototypes.

• One used traditional breadboards and a 3D-printed object
• The other used only a CurveBoard of the object

“Both sections designed the same prototype but switched back and forth between sections after completing designated tasks,” said MIT. “In the end, five of six of the participants preferred prototyping with the CurveBoard. Feedback indicated the CurveBoards were overall faster and easier to work with.”

It added that CurveBoards are not designed to replace breadboards.

“People love breadboards, and there are cases where they’re fine to use,” said Zhu. “This is for when you have an idea of the final object and want to see, say, how people interact with the product. It’s easier to have a CurveBoard instead of circuits stacked on top of a physical object.”