The aim of the innovative Physical Internet (PI) concept is to reverse the unsustainability situation existing in current logistic systems. In the PI approach, the goods are encapsulated in modularly dimensioned, reusable or recyclable and smart containers, called PI-containers. This paper focuses on the design of such containers and more particularly on their associated activeness. This capability allows the PI-container to have an active role for its mission and in the PI management and operation. After a presentation of the physical and informational requirements associated to PI-containers, the notion of activeness is detailed and the main research issues are presented.