Printem: Instant Electronic Circuits in 3 minutes

What it does

Our invention empowers anyone with access to an unmodified home-office printer to build flexible circuits under 3 minutes. Absolutely no harmful chemicals or special machines involved - simply print on our film, expose to light and peel to reveal the circuit.

Your inspiration

As engineers with experience building electronics, we were frustrated by the week-long wait times between sending a printed circuit board (PCB) design for fabrication and receiving a prototype to test. We looked for solutions to make PCBs instantly and found that the innovation was always around building special machines - machines are expensive, unreliable and require maintenance. Hence, inspired by polaroid film, we created a smart material (the Printem Film) - that works with easily accessible machines, such as commodity office printers or smart phones to fabricate PCBs instantly and make electronics truly accessible everyone.

How it works

Printem is a multilayer stack of different photosensitive materials that work together to create the final copper circuit patter. The key factor involved in it is the principle of selective adhesion, printing on the Printem Film with a normal office printer creates a photo-mask, which only lets light through the film in sections where the ink is absent. Then, when the Printem film is exposed to light, the light penetrates the layers of the material and initiates a reaction that selectively "sticks" the copper to the substrate. When the user peels the circuit as shown in the youtube video. The copper 'tears' in exactly the right pattern to create the final circuit, all in under 3 minutes. We are also working on a variant that can skip the Printing step completely and use images displayed on normal laptops and cellphones to create the circuits. We sincerely request you to see the youtube video attached with the application before proceeding with the evaluation.

Design process

We were inspired by the photolithography process used in PCB fabrication houses – we wanted to re-engineer this process but use machines people already owned, such as printers or cell phones, to create circuits. We developed the ‘smart material’ with this core requirement/constraint in mind. The first iteration of the Printem Film (video included in the submission) used a printer and cured under UV light. The user printed the negative of a circuit design on the ‘smart material’ using an unmodified printer and exposed to UV light – in about 2 minutes the circuit design cured within the self-contained ‘smart material’. We tested this version with several users, from middle school kids to hardware companies, and found that the need to use a UV light was still a major obstacle. Hence, we decided to create a version that uses light at wavelengths in the visible spectrum to cure. The current iteration of the Printem Film can cure when exposed to light from phone screens. All the user needs to do is place the Printem Film on phone/tablet/laptop screen with the circuit design and hold for about 3 minutes. Once the curing is done, the user needs to peel the top layer to reveal the Copper pattern.

How it is different

While we do appreciate the engineering required to build complex circuits at scale, we fundamentally believe that the ability to build, test and iterate single-layer circuit designs instantly at low cost will drive hardware development costs down and increase access to building electronics. The solution we’ve engineered packages the processes that happen at a PCB fabrication facility into one single film, thus eliminating the need for special machines. Users can now go from designing a circuit to a prototype that can be tested in about 3 minutes at a cost of about $15 - $20 (USD). In addition, the technology is built for flexible substrates and this opens a wide range of applications that are currently inaccessible. To summarize, our solution is: • Instant (~3 minutes) • Low cost (~$15-$20 USD) • Flexible • Customizable

Future plans

Technology: We are now working on the chemistry of our materials to ensure users can solder components. In the next iteration of our product, users will be able to create circuits directly on any surface without the need for a substrate. Business: We project to start selling the films by the end of the year. Our initial target is those who prototype electronics, but the bigger opportunity stems from the flexible form factor. We envision a world where end consumers, given designs, can create custom sensors, touch panels, circuits etc. and deploy it in the form factor of ‘stickers’ to ‘smarten’ anything.

Awards

RBC Graduate Innovation Fellowship Award University of Toronto Invention of the Year Award