Assistive System for Signed Alphanumeric Spelling: a communicative mediation

Brazilian Sign Language (LIBRAS) is a vital means of communication for the Deaf community, with signed alphanumeric spelling serving as a fundamental resource for spelling out proper names, acronyms, and specific terms. However, there are few accessible assistive technology solutions designed to physically reproduce the alphanumeric characters used in this context. This paper presents the development of an assistive upper-limb system for signed alphanumeric spelling, based on a 3D-printed robotic hand controlled by an ESP32 microcontroller and operated via a mobile app over Bluetooth. The system was developed using the open-source DexHand V1.0 platform, which was adapted to simplify the mechanics, reduce costs, and improve reproducibility. The results demonstrated the feasibility of reproducing signed alphanumeric spelling, highlighting the solution's potential as an assistive, educational, and research tool.