Innovators from Purdue University hope their new technology can help transform paper sheets from a notebook into a music player interface and make food packaging interactive.
Purdue engineers developed a simple printing process that renders any paper or cardboard packaging into a keyboard, keypad or other easy-to-use human-machine interfaces. For further information see the IDTechEx report on Smart and Intelligent Packaging 2020-2030.
"This is the first time a self-powered paper-based electronic device is demonstrated," said Ramses Martinez, an assistant professor in Purdue's School of Industrial Engineering and in the Weldon School of Biomedical Engineering in Purdue's College of 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."
Martinez said this innovation facilitates the fabrication of vertical pressure sensors that do not require any external battery, since they harvest the energy from their contact with the user. For further information see the IDTechEx report on Triboelectric Energy Harvesting and Sensing (TENG) 2020-2040.
This technology is compatible with conventional large-scale printing processes and could easily be implemented to rapidly convert conventional cardboard packaging or paper into smart packaging or a smart human-machine interface.
"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 said. "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."
The fabrication of multifunctional electronic devices on ubiquitous paper substrates is gaining considerable attention due to their low cost, environmental friendliness, light weight, and flexibility. Unfortunately, the development of paper-based electronics is subject to significant challenges, such as rapid degradation with moisture, battery dependence, and limited compatibility with existing mass production technologies. This work describes omniphobic, self-powered paper-based electronics (RF SPEs), completely wireless paper-based electronic devices insensitive to moisture, liquid stains, and dust. RF SPEs can be rapidly fabricated through the sequential spray-deposition of alkylated organosilanes, conductive nanoparticles, polytetrafluoroethylene (strong electron affinity), and ethyl cellulose (weak electron affinity) over the surface of cellulose paper. RF SPEs are lightweight, inexpensive to print (<$0.25 per device), and capable of generating power densities up to 300 µW/cm2. Additionally, RF SPEs are flexible and exhibit excellent stability upon folding (0.3 mm radius of curvature). The simple printing process and relative low cost of RF SPEs enable the large-scale production of self-powered paper-based electronics towards the ubiquitous integration of human-machine interfaces.
Source and top image: Purdue University