PhD Research: Towards Affordable Tactile Displays for Inclusive Education

Children who are blind or partially sighted face significant challenges in accessing Science, Technology, Engineering, Arts, and Mathematics (STEAM) education due to the primarily visual nature of its content. Traditional tactile tools such as Braille books, embossed graphics, and other custom-made resources often fail to provide the flexibility, interactivity, and depth needed for subjects like mathematics, science, and design. This issue is particularly critical in lower- and middle-income countries, where resources are limited and prevalence of childhood blindness is higher.

In response to this global accessibility challenge, and building on the theoretical foundation laid in Tigmanshu Bhatnagar’s doctoral research at UCL’s Global Disability Innovation Hub, this project focuses on the design and development of affordable, refreshable tactile display technologies. These technologies aim to make STEAM content more accessible and engaging for learners with visual impairments.

Project Overview

The primary research outcome is Tacilia, a low-cost, reconfigurable multiline tactile display designed to present both Braille and tactile graphics on a single interface. Developed through interdisciplinary collaboration at UCL with support from institutions including IIT Delhi and the Global Disability Innovation Hub, Tacilia directly addresses UN Sustainable Development Goal 4: Quality Education for All.

The development process began with field studies in schools for visually impaired students in India, where current teaching methods rely heavily on printed tactile materials. These tools are often bulky, expensive to produce, and poorly suited for interactive or conceptual subjects such as graph analysis, spatial design, or programming.

Recognising the lack of accessible and affordable tools for these contexts, the project focused on creating a refreshable tactile display that could better support modern pedagogical needs. Tacilia emerged from this research as a novel, scalable, and low-cost alternative to commercial devices currently priced at over £10,000.

Key Findings and Contributions

1. User-Informed Design

Rather than imposing a top-down solution, the development of Tacilia was grounded in continuous feedback from blind and partially sighted learners and educators. This participatory design approach led to the rejection of several technically feasible concepts in favour of designs that users found more intuitive and meaningful.

2. Novel Actuation Technology

At the core of Tacilia is an innovative actuation mechanism utilising Nitinol, a shape-memory alloy activated by heat. The device consists of an array of Nitinol pins heated by micro-heaters that raise the pins to form Braille characters or tactile graphics. These pins can be reset, allowing for erasable, refreshable interactions. This novel approach enables a compact and affordable interface that supports both text and images, essential for STEAM learning.

3. Digital Integration and Multimodal Access

Tacilia’s actuation system is digitised, allowing computer-generated content to be rendered directly on the tactile surface. This enables a seamless integration of tactile and audio interfaces, helping learners better understand and interact with complex materials. Future plans include plug-and-play compatibility with smartphones, tablets, and computers.

4. Scalability and Affordability

The low component cost and scalable design architecture of Tacilia position it as a viable solution for widespread educational deployment in both high-income and resource-constrained settings. Its minimalist hardware requirements make it particularly suitable for classrooms in low- and middle-income countries.

5. Toodleoo: Erasable Tactile Drawing Interface

Thanks to support from the UCL–IIT Delhi Strategic Partnership Seed Fund, a complementary project titled Toodleoo was also developed. This erasable tactile drawing interface enables blind and partially sighted users to intuitively create and erase tactile sketches on a reconfigurable smart surface using a specially designed pen. While not the central focus of the research, Toodleoo explores novel applications of tactile display technologies for creative expression and conceptual learning, particularly within STEM contexts.

Impact and Future Work

Tacilia has already demonstrated potential to transform tactile literacy and STEAM education for blind learners. With continued support, the project is moving toward commercialisation, with the goal of making this technology globally accessible. 

Areas of future exploration include:

• Increasing display size and resolution
• Improving interface compatibility with digital devices
• Expanding language support and localisation
• Hiring technical staff for rapid prototyping and engineering

The work exemplifies how inclusive, user-centred design and material innovation can converge to address critical accessibility gaps in global education systems.

Publications

• PRET Printer: Development and Evaluation of a Passive Refreshable Tactile Printer (2024)
• Brilliance and Resilience: A New Perspective to the Challenges, Practices and Needs of University Students with Visual Impairments in India (2023)
• Designing a New Tactile Display Technology and its Disability Interactions (2023)
• Pixelated Interactions: Exploring Pixel Art for Graphical Primitives on a Pin Array Tactile Display (2023)
• Analysis of Product Architectures of Pin Array Technologies for Tactile Displays (2023)
• Drawing Erasable Tactile Diagrams on Tacilia (2021)

Explore Tacilia's website