Flexible, thin electronics are making strides to revolutionize the way we interact with our devices. From peel-and-stick solar cells to recyclable paper USB drives, the future is trending towards thin and pliable gadgets. Now, developments in printing technology are making strides towards producing transparent transistors on flexible nanopaper. These types of advances could be the next step towards producing printable and renewable electronics.
A team of scientists at the University of Maryland, College Park has been successful in creating a transistor from nanopaper that is both highly transparent and flexible. The nanopaper was created by treating paper pulp with oxidizing chemicals, giving the material cellulose fibers with the average diameter of 10nm. The researchers then built transistors on the paper by adding layers of carbon nanotubes, an insulating organic molecule, and a semiconducting organic molecule. The device was then finished with electrodes also composed of carbon nanotubes. In addition to acting as an electrode for the transistors, the carbon nanotubes also created a structural backbone and preventing wrinkling.
Due to its optical transmittance and roughness, nanopaper is able to create electronics not possible on regular paper. For the first time, the engineers demonstrated that flexible transparent organic field-effect transistors (OFETs) with carbon nanotube networks as source/drain contact could be added to the paper. When bent, there was only a 10% decrease in the transistor’s efficiency. Developing nanopaper-based transistors could represent “another step down the road to renewable printed electronics,” Jeffrey Youngblood, a materials engineer at Purdue, told CEN.