Researchers at Carnegie Mellon University have developed a paper attached to a conductive material that can track touch and transfer the written data to a device in real time. The paper itself is your typical, run-of-the-mill paper, but conductive material is applied to the back. While looking for the best conductive material to attach to the paper, the researchers wanted to make sure it was as inexpensive as possible and could be applied in a high-volume production scenario.
Many materials were eliminated due to high costs, non-scalability and poor interaction with paper, but the researchers found two that were suitable -- a carbon-loaded plastic sheet that can be adhered to the paper and carbon-loaded paint that can be silk-screened, brushed or sprayed on.The paper is connected to a sensor board which allows touch from a finger, a pen or a stylus to be digitised. The paper costs around ₹20 per sheet.