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VISTA - Haptic Museum Display

Archived
Timeline

Oct 2025 - Dec 2025

Role & Context

Haptics & Assitive Technology

Core Tech
Fusion 360ArduinoC++Soft Robotics

Project Summary

Designed a tactile display (VISTA) with a 7x5 pin array to convey art structure and appearance to visually impaired individuals.

Key Features

  • 7x5 pin array with independent cam-actuated height control
  • Color-to-Height mapping algorithm (Yellow > Red > Blue > White)
  • Silicone overlay (Ecoflex 00-30) for continuous tactile surface
  • Distributed Arduino control architecture handling 35 servos

Impact & Takeaways

  • Achieved 100% success rate in shape recognition (Flag Identification Study)
  • Demonstrated feasibility of multi-modal encoding (Shape + Color via Height)
  • Validated the need for a tactile legend to improve color distinguishability

Context & Motivation

According to the American Alliance of Museums, 7 million visually impaired individuals in the US face a largely inaccessible cultural landscape. This project introduces VISTA (Visual Information through Sensory Tactile Array), a novel tactile display designed by our team to convey both the structure and appearance of art through touch.

System Architecture

The system utilizes a 7x5 pin array where Shape is rendered by actuated pins and Color is encoded via variable pin height.

Input Image Processing / Python
Downsample (7x5)
Mapping Logic Color → Height → Angle
Servo Cmds
Physical Array 35x Cam Actuators

Engineering Implementation

Mechanical Actuation & Constraints

The device requires precise independent control of 35 pins. I optimized the mechanical packaging to bring the pins as closely together as possible:

CAD Design of Pin Array
  • Cam Design: The cams have a 1.5" pitch radius to achieve the 4 distinct height levels. This necessitated a pin spacing of 1.6 inches, creating a coarse but intelligible grid for palm-based interaction.
  • Silicone Interface: To bridge the gap between discrete pins and a continuous image, the team designed and fabricated a Smooth-On Ecoflex™ 00-30 silicone overlay. The surface was coated in cornstarch to reduce friction and utilized a 3-level tensioning system to optimize tactile transmission.
Silicone Overlay Prototype

Electronics & Logic Pipeline

The team developed a control system to translate pixel data into physical topography using a custom mapping algorithm:

  • Color-to-Height Mapping: We quantized colors into 4 discernable height levels to convey depth:
    Yellow (17.5mm) > Red (9.8mm) > Blue (6.3mm) > White (2.7mm)
  • Distributed Control: The team implemented an electronic architecture with two Arduino boards managing 35 servo motors (one per pin) to handle the high PWM channel load. Each pin was actuated individually to render an image to ensure the servo motors did not surpass the Arduinos’ current limits.
Electronics Schematic

Performance & Results

We validated the device using a "Flag Identification" study (Japan, Sweden, Denmark) to test shape vs. color recognition:

  • Shape Recognition: 100% of participants successfully distinguished flags with differing geometries (e.g., Japan vs. Sweden).
  • Color Distinguishability: While pure color differentiation (Sweden vs. Denmark) proved challenging (35% error rate initially), the addition of a tactile legend allowed users to accurately map height to color.

Demos

Japan Flag Demo

Denmark Flag Demo

BACKEnd of File