Vision impairment limits a person's ability to communicate, to learn, to work, and to travel. In the United
States alone, there are 1.3 million legally blind, including 55,000 children. Traditionally, blind children were taught
with Braille as the written medium. However, in recent years, literacy rates among the blind have declined to
alarmingly low levels, primarily due to the rapid advancement of cheap and accessible audio devices. While
audio devices have improved individual access to information, Braille and other tactile medium are important for
forming connections between concepts and physical objects. More importantly, Braille literacy directly correlates
with success in high education and employment. The majority of the blind people who are employed are Braille
readers. Unfortunately, Braille devices have remained bulky and expensive, relying on aging technologies.
Refreshable Braille devices currently on the market are limited to 1 or 2 lines of characters (Braille cells), which
limits their display capabilities to pure text. There is an urgent need to employ modern technologies to develop
low-cost devices that enable communication, simplify education, and ensure the vision impaired are fully
integrated into society.
The objective of this project is to develop a Braille electronic display panel that can assemble into compact
form factors such as smartphone cases. The panel will consist of an array of raised dots that can display Braille
text and topographical patterns representing graphics, maps, symbols, and more. The display content will be
refreshable akin to images on a smartphone screen. The target Braille panel, to be named PolyPad, will exploit
a variable stiffness polymer which we have recently innovated. The polymer exhibits a modulus change from
~100 MPa to ~0.1 MPa in a narrow temperature range of 40-45 oC. The large variable stiffness allows for large-
strain deformation in the softened state by relatively low pneumatic pressures, and for high shape fixation rate
and supporting force in the rigid state. Our preliminary study has also led to a highly compliant Joule heating
electrode that can electrically supply the temperature change for the polymer membrane and consequently alter
its stiffness. The driving voltage is on the order of 12 V; off-the-shelf, high-efficiency circuits could be employed.
The project will investigate the essential materials, processes, and structures needed to fabricate high-
performance PolyPad devices. The proof-of-concept PolyPad devices will be evaluated throughout the project,
providing formative user data throughout development and summative evaluation. Qualitative data will be
collected through the use of surveys and rating scales, and quantitative data on usability will include speed and
accuracy in reading and identifying graphic text.