A typical sheet of paper or cardboard is neither waterproof, interactive or able to harvest energy, but an innovative new printing technology developed at Purdue University can make it all of the above. The researchers demonstrated the technique by transforming a sheet of notebook paper into a music player, and say it could be scaled up to work with larger printing processes for more mainstream uses.
“This is the first time a self-powered paper-based electronic device is demonstrated,” says study author Ramses Martinez, an assistant professor in Purdue’s School of Industrial Engineering. “We developed a method to render paper repellent to water, oil and dust by coating it with highly fluorinated molecules. This omniphobic coating allows us to print multiple layers of circuits onto paper without getting the ink to smear from one layer to the next one.”
With this omniphobic coating as the starting point, the researchers were able to integrate vertical pressure sensors onto the paper. This not only enables it to become an interactive surface for a variety of applications, but also one that can harvest energy from user’s actions through friction as they apply pressure to the device, which can be used to power wireless Bluetooth communication.
The team demonstrated the new technology by turning it into a keypad capable of wireless data transmission, and even more impressively, into a musical player. This paper-based instrument can respond to touch and drag gestures to turn volume up and down, and features buttons printed onto the paper to mute and to skip to the next song.
Importantly, the team says these devices are cheap to print, at less than US$0.25 per device, and that the technology is compatible with typical printing processes. This means it could therefore be easily adapted to turn things like cardboard packaging into smart packaging, for example.
“I envision this technology to facilitate the user interaction with food packaging, to verify if the food is safe to be consumed, or enabling users to sign the package that arrives at home by dragging their finger over the box to properly identify themselves as the owner of the package,” Martinez says. “Additionally, our group demonstrated that simple paper sheets from a notebook can be transformed into music player interfaces for users to choose songs, play them and change their volume.”
You can see a demonstration of the music player in the video below, while the research was published in the journal Nano Energy.
Source: Purdue University