This Small Business Innovation Research (SBIR) Phase I project responds to the ubiquitous and growing demand for electronic displays by investigating the feasibility and performance of a low-cost, flexible electronic paper solution, targeting high contrast, fast response, and low power consumption. The intellectual merit of this investigation is the advancement of a new display technology that will change the way information is viewed and presented, and the manner in which electronic displays are produced. A key technological innovation is the development of a paper-like porous matrix to control the motion of charged nanodroplets under applied electric fields. The two specific research objectives are: (1) to develop a low-cost, nanodroplet-compatible porous matrix, and (2) to integrate the porous matrix into a flexible display. Research activities for the first objective involve formulating the matrix, establishing deposition method, quantifying material characteristics, measuring ink interactions, and testing basic (single-pixel) operation. Research activities for the second objective involve integrating the porous matrix and ink into a flexible display, testing multi-pixel operation, and determining optimal performance limits. Anticipated results of this Phase I project are a quantitative understanding of this innovation and identification of some key manufacturing processes leading into further development in Phase II.
The broader impact/commercial potential of this project include the creation of a disruptive new display technology, mitigation of environmental factors associated with manufacture and disposal of thin-film transistor (TFT) displays, energy efficiency, reduced paper consumption, and expanded yet economical use of electronic displays for visual communication. This project has high potential for significant commercial impact because it addresses the need for a high-performance, low cost, energy efficient display solution within the rapidly growing global display market, which is currently valued in excess of $150B. The enhanced scientific understanding that will be gained from the study of matrix and nanodroplet interactions will contribute to aggregate knowledge of nanoscale systems, and has potential for synergies beyond the realm of electronic displays, with commonalities encountered in fields such as bioseparation processes and photovoltaic devices. Another important aspect of this research is its impact on education through the engagement of a faculty member and graduate students at one of the nation's minority serving universities in a joint research endeavor. This partnership fosters integration of contemporary industrial relevance with academic learning for a diverse audience of future engineers and scientists.
This project demonstrated the feasibility of using a nanodroplet-based electro-responsive ink within a porous "paper" medium to create low-cost, flexible, power-efficient, paperlike electronic displays. The focus of the study was primarily the development and demonstration of the "paper" component of the ink-and-paper system. The paper component is a direct analogue to traditional paper, providing physical structure to the display, a white background, and a porous medium to hold the ink. The paper is infused with the colored ink, and the ink is subsequently moved within the paper by externally applied electric fields to create an image. This conceptually simple and low-cost approach to making paper-like electronic displays is enabled by recent advances in nanotechnology and our evolving understanding of nano-scale phenomena. Specific achievements of this project include the development of compatible "paper" formulations using low-cost production processes, and demonstration of four-pixel, flexible displays. These displays have paper-like viewability, contrast of approximately 5:1, and peak whiteness of approximately 50%. Driven at ± 2.5 V, these power-efficient displays use less than 10 µW per square inch, and are partially bistable, retaining the image at no power for up to several minutes. Based on low materials cost and simple manufacturing methods, unit cost in volume production is expected to be significantly lower than current lowest-cost display options based on passive LCD.
