Designing Foldable Helmets for Micro-mobility using Sustainable Materials

Abstract

Background Micro-mobility is a form of transportation that travels short distances using lightweight vehicles such as e-scooters or e-bicycles. Micro-mobility is now prevalent in major cities worldwide and is seen by many users of urban areas as an alternative to motor vehicle transport. Micro-mobility offers considerably higher speeds than walking, is more environmentally friendly and convenient than driving, and does not require expensive car-parking facilities. A helmet is vital personal protective equipment that significantly reduces the risk of head injuries resulting from falling while using micro-mobility services. However, many users do not use a helmet or wear a traditional bicycle helmet despite the much higher speeds while riding micro-mobility. By considering user behavior, designing micro-mobility helmets should consider protecting riders' head injuries, wearing comfort, and maximizing the portability to be easy to carry. In addition, from an environmental perspective, the material used for the current mobility helmet market is far from eco-friendly. As user demand increases, it is time to examine the application of sustainable materials for helmet production. To meet the aim of this study, we explore the various materials to satisfy the essential function of helmets for riders of micro-mobility (e.g., safety, comfortability, portability) along with promoting sustainability. This study seeks to encourage more riders to wear helmets while using micro-mobility to prevent head injuries. Therefore, the developed helmet should be easy-to-carry, comfortable to wear, lightweight and portable. Methods To promote the use of environmentally friendly products, this study evaluated various eco-friendly materials that can design a highly portable form of the final product at the design stage. This study considered two sustainable materials for helmet production: corrugated cardboard and cork and one recyclable material, Nylon 66, from automobile airbags. Finally, using finite element analysis (FEA) and computational fluid dynamics (CFD) analysis, this study tested all the proposed final designs to examine if the designed helmets meet the applicable safety standards and their functional requirements. Results The FEA analysis showed that the corrugated paper helmet was superior in relation to the stress on a rider's head, recorded as 5KPa at 80km/h. The CFD analysis revealed that the cork helmet showed better performance in terms of the temperature of a rider's head. The cork helmet reduced the temperature by 3.6 ℃ from an initial head temperature set at 36.5 ℃ . Conclusions Considering broad design factors, portability, cooling capacity, and eco-friendliness, corrugated paper was the most suitable helmet material for producing micro-mobility users. However, future work should consider more aesthetic and stylistic elements of helmet design.