TWIICE: a device designed to meet a variety of pathologies, morphologies and expectations Origin of the project and motivations The development of a modular exoskeleton for walking assistance began in February 2015 at the Laboratoire de Systèmes Robotiques (LSRO) at EPFL. A year and a half later, the device is already operational for the first tests with a pilot. TWIICE allows users to regain independence through daily activities: sitting and standing, walking on regular, rough or tilted surfaces, climbing stairs or interacting in community. Our intention is trying to give back users part of the sensations associated with walking or standing. Every disability being unique, one single exoskeleton alone cannot fulfill all expectations. Hence the need for a modular and customizable device. With a weight of 15 kilos and a battery enabling 3 hours of active walking, TWIICE is designed to handle different pathologies, morphologies and user experiences. The whole technical design is developed with a special emphasis on simplicity, which confers robustness, reliability and lightness to the device. Silke Pan, in the heart of the technological development The development of such a device would not be possible without the close involvement of its direct beneficiaries. By their unique perspective they allow engineers to understand their expectations and needs in order to guide future developments. When searching for talented pilots, the EPFL team approached the Swiss Paraplegic Foundation. The organization redirected them to the Wheelchair Club Lausanne. Ms Silke Pan thus heard of the project through one of the club members and responded enthusiastically. Since July 2016, Ms Pan has piloted the exoskeleton periodically two or three times per week. Her help contributed to many enhancements such as the adjunction of a system of auditory feedback. It helps to synchronize her own actions with TWIICE: the first signal indicates her foot detachment and the second one the end of the cycle, in other terms the return of the weight on the foot.