According to associate professor John Hart, the team’s stamping process should be able to print transistors small enough to control individual pixels in high resolution displays and touchscreens.
“There is a need for printing electronic devices that are inexpensive but provide simple computations and interactive functions,” Hart explains. “Our printing process is an enabling technology for high performance, fully printed electronics, including transistors, optically functional surfaces, and ubiquitous sensors.”
To make their stamps, the researchers grew the carbon nanotubes on a surface of silicon in various patterns, including honeycomb-like hexagons and flower-shaped designs. They coated the nanotubes with a thin polymer layer and then infused the stamp with a small volume of electronic ink containing nanoparticles such as silver, zinc oxide, or semiconductor quantum dots.
The team developed a model to predict the amount of force necessary to stamp an even layer of ink onto a substrate, given the roughness of both the stamp and the substrate, and the concentration of nanoparticles in the ink.
“The next step is the integration of our printing technologies with 2D materials, such as graphene, which together could enable ultrathin electronic and energy conversion devices,” Hart says.
