Multimodal 3D printed urban maps for blind people. Evaluations and scientific investigations
Malgorzata Telesinska · 2023 · ASSETS 2023: The 25th International ACM SIGACCESS Conference on Computers and Accessibility · doi:10.1145/3597638.3614503
Summary
This poster paper presents a multimodal 3D printed urban map prototype that embeds capacitive touch sensors directly into the map body to provide location-specific audio descriptions when touched. The research, conducted at Wroclaw University of Science and Technology in Poland, addresses the challenge of conveying spatial information about urban environments to people with visual impairments. Unlike previous approaches that rely on companion smartphones, external clicking mechanisms, or pin-matrix displays, this solution uses multimaterial fused filament fabrication (FFF) 3D printing to seamlessly integrate conductive PLA electrodes (ProtoPasta Conductive PLA) into the standard PLA map body. The electrodes function as zero-dimensional self-capacitance touch sensors, where the user's finger and the electrode form a capacitor detected by a capacitive touch sensor controller. Double-tapping a location triggers a microcontroller to play the corresponding pre-recorded audio description through a connected headset. The map model represents a fictional city fragment with ten buildings of varying shapes and sizes, designed by architects to test spatial comprehension without prior topographic knowledge. The construction process uses Rhinoceros 6 CAD software for 3D geometry and Cura slicing software, printed on a Prusa i3 MK3S+ with MMU2S multi-material upgrade, with variable layer heights between 80 and 200 micrometers.
Key findings
An initial usability study with eleven participants with visual impairments (ages 18-62, mean 31.64) yielded positive results across three assessment areas. For user experience and usability, participants rated the device favorably: they liked it (S1: median=3 on a 7-point scale where lower is more positive), found it useful (S5: median=6), convenient (S10: median=2), and attention-catching (S9: median=6). For accessibility, participants reported they could use the device independently (S2: median=6), it required minimal technical knowledge (S3: median=2), audio did not obstruct tactile reading (S4: median=5), and triggering information was easy (S7: median=2). Critically, participants would willingly use the device and recommend it to others (S6: median=7, S8: median=1). For memorability, participants recreated the map layout from memory by placing detached building blocks on a blank canvas. Positioning accuracy was highest for objects with unique shapes (L2: median=2.7cm, SD=1.69; L9: median=2.2cm, SD=1.18), suggesting correlation between audio descriptions and shape distinctiveness aided spatial recall. The overall mean positioning error was 3.53cm, approximately 17% of the canvas side length. Participants learned to operate the device within thirty seconds and engaged enthusiastically, with several noting the solution could eliminate the need for Braille knowledge or sighted assistance.
Relevance
This research demonstrates a promising fabrication technique for creating self-contained tactile maps that combine 3D spatial information with embedded audio without requiring external companion devices. For accessibility practitioners working in urban planning, museum exhibitions, or educational settings, the approach offers a relatively affordable method using consumer-grade 3D printers to produce interactive tactile models. The multimaterial printing technique that embeds conductive electrodes directly into the map body is particularly innovative, avoiding the fragility and geometric distortion of externally attached sensors. The strong user enthusiasm and the finding that thirty seconds of instruction was sufficient for independent operation suggest high practical viability. However, the study is preliminary with a small sample, the double-tap activation needs refinement to prevent accidental triggers, and the touch target locations need clearer tactile marking. Future work should address outdoor weather resistance, scalability to larger and more complex urban areas, and integration with smart city infrastructure.
Tags: tactile maps · 3D printing · blind and low vision · multimodal interaction · audio-tactile · urban accessibility · spatial cognition · haptic devices · smart cities
Standards referenced: ISO accessibility standards