555/716 ©2022 Jayasree et al. doi:10.5075/epfl-298799_978-2-9701614-0-0 published under CC BY-NC 4.0 license This conference paper is part of a six volume book of the proceedings edited by: Prof. Anastasios P. Vassilopoulos, CCLab/EPFL, Prof. Véronique Michaud, LPAC/EPFL. All six volumes will have the same title and each will have a single subtitle: Vol 1: Materials Vol 2: Manufacturing Vol 3: Characterization Vol 4: Modeling and Prediction Vol 5: Applications and Structures Vol 6: Life Cycle Assessment. Copyright © 2022 Jayasree et al.. Low-speed accidents see a year-on-year increase. To improve crash performance in these accidents, a crash box is attached between the vehicle bumper structure and the side rail. The determination of the crash box material and geometry is critical to absorb the impact energy to result in safer vehicles and minimised repair costs. As the automotive industry transitions to more sustainable platforms, it is seeking to use lightweight materials including in the crash structure. This study develops an innovative crash box with optimal impact energy-absorption capabilities for a fuel cell electric vehicle. The concept is based on topology optimisation considering the composite structure and crash energy dissipation. In further work, the results from the life cycle analysis are utilised, and a comparative study between carbon fibre reinforced polymers and biocomposites in crash structures is performed. The latter includes an extensive characterisation campaign under static and dynamic conditions. Keywords: Composites; crash box; The PROTECT project has received funding from Innovate UK under reference number 68148.