Oral title: Concept studies for a Planet Formation Imager

Oral abstract: The "Planet Formation Imager" project aims to develop the roadmap for a next-generation interferometric facility that 
will be able to witness the  processes involved in planetary birth on the natural spatial scales where the material is assembled. In 
this talk we present the key science drivers of PFI and discuss the technologies that we investigate in order to meet the 
specifications.