Animations at Your Fingertips: Using a Refreshable Tactile Display to Convey Motion Graphics for People who are Blind or have Low Vision
Leona Holloway, Swamy Ananthanarayan, Matthew Butler, Madhuka Thisuri De Silva, Kirsten Ellis, Cagatay Goncu, Kate Stephens, Kim Marriott · 2022 · Proceedings of the 24th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '22) · doi:10.1145/3517428.3544797
Summary
This paper investigates the potential of refreshable tactile displays (RTDs) to convey animated graphics to people who are blind or have low vision — a capability that has been virtually impossible with traditional static tactile media. While tactile graphics produced on swell paper or through embossing have long been the standard for making visual information accessible through touch, they are inherently static and cannot represent movement, change over time, or dynamic processes. RTDs, which use grids of electronically controlled pins that can be raised and lowered, offer the possibility of displaying sequences of tactile images — essentially tactile animations. The research proceeded in three phases. First, an online survey of 19 touch readers and 7 vision accessibility experts identified the most desired applications for tactile animations. Education and science topics (astronomy, geographic movement, biology) ranked highest, followed by orientation and mobility applications (maps with routes, traffic movement) and concept development (modes of flying, human movement). The researchers then undertook an extensive design exploration phase using a Graphiti RTD — a commercially available 60x40 pin display costing USD $25,000. Working collaboratively with a blind touch reader (Stephens, a co-author), they created and iteratively refined a wide range of tactile animations including ocean waves, waterfalls, maps with moving cursors, Tai Chi movements, solar eclipses, bird flight, plant growth, and animated GIFs. This process yielded important design insights about simplification, the use of pin height to convey depth, texture patterns for area distinction, and the impact of the display's top-down refresh direction on animation readability. Finally, a formal user study with 12 blind adults compared four tactile animations on the RTD against equivalent static tactile graphics produced using traditional swell paper and collage techniques. The four test animations — wave formation, waterfall formation, a city map with route, and Tai Chi movements — were selected to represent different types of motion and complexity.
Key findings
The RTD was preferred overall (25 vs 17 preferences for tactile graphics, with 6 equal), particularly for detecting change between frames (24 vs 17) and conveying a sense of direction and motion (20 vs 13). However, traditional tactile graphics were moderately preferred for initial understanding of static images (21 vs 17) due to their higher resolution, richer textures, and better contrast between different areas. The wave and waterfall animations were the most successful on the RTD, as changes were localised to small areas and followed predictable paths. The wave animation could run at near real-time speed (2.25 seconds per frame). The Tai Chi sequence was least successful because simultaneous movement across multiple body parts was too complex to follow by touch. Participants drew parallels to watching movies, with one exclaiming "it's like looking at a motion picture." Pin height proved valuable for conveying 3D information — participants found the RTD's variable pin heights more intuitive than swell paper's use of solid versus dashed lines to indicate depth. A key unexpected finding was the advantage of real-time editability: researchers could immediately modify diagrams based on participant feedback, something impossible with printed tactile graphics. The average System Usability Scale score was 79.9, interpreted as "good." Participants suggested applications in education, orientation and mobility, sports, entertainment, and content creation.
Relevance
This research opens a significant new frontier in accessible graphics by demonstrating that tactile animations are both feasible and valued by blind users. For accessibility practitioners, the paper provides practical design guidelines for creating animated content on RTDs: simplify graphics significantly compared to static versions, use pin height strategically, restrict movement to one region at a time, consider the display's refresh direction when designing animations, and use blinking pins to direct attention. These guidelines are immediately applicable as RTD technology becomes more affordable and widespread. The findings also highlight important trade-offs that inform procurement and deployment decisions. RTDs excel at conveying change and motion but sacrifice resolution and textural richness compared to traditional tactile graphics, suggesting the two formats are complementary rather than one replacing the other. The high cost of current RTDs (USD $25,000) remains a significant barrier, though the zero marginal cost per image and the ability to edit in real time offer compelling advantages for educational settings, libraries, and institutions serving blind communities.
Tags: tactile graphics · refreshable tactile display · blind users · low vision · animation · tactile animation · accessible graphics · education