The article studies four platforms of a micro- and nanotechnology cluster, and analyzes them as infrastructures. The observation of the concrete practices that shape platforms shows a tension between the pooling of resources, crucial for the legitimization of this policy instrument, and the making of organizational models that fit for the diversity of experimental activities. It points out that,
... [Show full abstract] in some cases, some minimal forms of pooling are fostered in order to manage the contradictions of platform organization and to keep some rooms for maneuver in experimental practice.