Perumal Varun Chadalavada and Gowtham Ramachandran from the University of Toronto were frustrated by the week-long wait between sending a printed circuit board (PCB) design for fabrication and receiving a prototype to test.
So they developed the Printem Film, a multilayer stack of different photosensitive materials that fits into a home printer 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. When the Printem film is exposed to light from a laptop or phone, the light penetrates the layers of the material and initiates a reaction that selectively "sticks" the copper to the substrate. When the user peels back the layers, the copper 'tears' in exactly the right pattern to create the final circuit, all in under 3 minutes and for US$15 to $20. .
The current iteration of the Printem Film can cure when exposed to light from phone screens but the team is now working on a variant that can skip the Printing step completely and use images displayed on normal laptops and cellphones to create the circuits, as well as working on the chemistry of the materials to ensure users can solder components onto the cirtuits reliably.
The students plan to start selling the films by the end of the year for prototype electronics with the aim of developing flexible systems such as custom sensors, touch panels, circuits etc. and deploy it in the form factor of ‘stickers’ to ‘smarten’ anything in the INternt of Things (ioT).
The two have won the RBC Graduate Innovation Fellowship Award University of Toronto Invention of the Year Award and were runners up in the 2018 James Dyson Awards for innovation.