Development of an electromechanical handbike prototype attachable to conventional wheelchairs

• A novel electromechanical handbike device was designed and constructed to transform conventional wheelchairs into electric-powered systems through a fast and secure coupling mechanism. • The proposed design prioritizes affordability, modularity, and user independence, addressing a significant need for low-cost mobility solutions in low- and middle-income countries. • The handbike integrates a compact motor drive, ergonomic control interface, and adjustable mounting system, enabling compatibility with a wide range of wheelchair models. • Performance validation tests, including speed, endurance, and terrain adaptability, demonstrated reliable operation and improved user mobility under real-world conditions. • This study contributes to inclusive technology development by offering a replicable and scalable mobility aid that enhances autonomy for people with disabilities. Mobility limitations among individuals with lower limb impairments often lead to overuse of the upper limbs, resulting in pain, fatigue, and long-term musculoskeletal injuries. Although electric wheelchairs improve mobility, their high cost limits access in low- and middle-income regions. To address this gap, we developed and evaluated a low-cost electromechanical handbike prototype designed to be easily coupled to standard manual wheelchairs. Using the V-model methodology for mechatronic systems, the design process included functional specification, Computer-Aided Design (CAD) modeling, structural simulation, and physical prototyping. The chassis was constructed from chromoly steel with a reinforced coupling mechanism, and the propulsion system integrated dual motors, a controller unit, and lithium-ion batteries. Structural simulations showed maximum von Mises stresses of 1.74 MPa on the fastener and 2.67 MPa on the chassis, with safety factors above 100, indicating strong mechanical performance. Field testing in Bucaramanga, Colombia—with participants using the device over varied terrain—demonstrated an average autonomy of 12.4 km per charge and high ergonomic adaptability. These results support the viability of a robust, affordable, and easy-to-maintain mobility solution. The proposed handbike enhances user autonomy and comfort, contributing to broader accessibility and improved quality of life for wheelchair users in resource-limited settings.