Andrew Steckl’s research is featured on the cover of the November issue of ACS Applied Materials & Interfaces.
A discovery by University of Cincinnati engineering researcher Andrew Steckl could revolutionize display technology with e-paper that’s fast enough for video yet cheap enough to be disposable.
In the research, Steckl and UC doctoral student Duk Young Kim demonstrated that paper could be used as a flexible host material for an electrowetting device. Electrowetting (EW) involves applying an electric field to colored droplets within a display in order to reveal content such as type, photographs and video. Steckl’s discovery that paper could be used as the host material has far-reaching implications considering other popular e-readers on the market such as the Kindle and iPad rely on complex circuitry printed over a rigid glass substrate.
The electrowetting device on paper is equivalent to that of glass, which is the gold standard in the field. With the right paper, the right process and the right device fabrication technique, you can get results that are as good as you would get on glass, and our results are good enough for a video-style e-reader.
Steckl imagines a future device that is rollable, feels like paper yet delivers books, news and even high-resolution color video in bright-light conditions.
“Nothing looks better than paper for reading,” said Steckl, an Ohio Eminent Scholar. “We hope to have something that would actually look like paper but behave like a computer monitor in terms of its ability to store information. We would have something that is very cheap, very fast, full-color and at the end of the day or the end of the week, you could pitch it into the trash.”
Disposing of a paper-based e-reader, Steckl points out, is also far simpler in terms of the environmental impact.
“In general, this is an elegant method for reducing device complexity and cost, resulting in one-time-use devices that can be totally disposed after use,” the researchers pointed out.
Steckl’s goal is attract commercial interest in the technology for next-stage development, which he expects will take three to five years to get to market.
The use of paper as a material for various device applications (such as microfluidics and energy storage) is very attractive given its flexibility, versatility, and low cost. Here we demonstrate that electrowetting (EW) devices can be readily fabricated on paper substrates. Several categories of paper have been investigated for this purpose, with the surface coating, roughness, thickness, and water uptake, among the most important properties. The critical parameter for EW devices is the water contact angle (CA) change with applied voltage. EW devices on paper exhibit characteristics very close to those of conventional EW devices on glass substrates. This includes a large CA change in oil ambient (90−95°), negligible hysteresis (2°), and fast switching times of 20 ms. These results indicate the promise of low-cost paper-based EW devices for video rate flexible e-paper on paper.