The Innovation Network aiming at Sustainable Smartphones (INaS) is an innovation lab at Leuphana University Lüneburg for sustainability pioneers from the smartphone value chain. It was founded in 2015 with the dual purpose of facilitating collaboration in the value chain and researching sustainability trans-formations. An initial workshop series from 2016-2018 addressed various sustainability challenges to co-create circular product and service innovations. Our second workshop series focuses on business opportunities for sustainable modular product design in the circular economy.