A High Resolution Tactile Display Based on Variable Stiffness Polymer and Pneumatic Actuation

NIH RePORTER · NIH · R01 · $347,185 · view on reporter.nih.gov ↗

Abstract

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. 1

Key facts

NIH application ID
10149323
Project number
5R01EY030246-02
Recipient
UNIVERSITY OF CALIFORNIA LOS ANGELES
Principal Investigator
Qibing Pei
Activity code
R01
Funding institute
NIH
Fiscal year
2021
Award amount
$347,185
Award type
5
Project period
2020-05-01 → 2025-04-30