Highly diffusable innovations create value across several domains and contribute to the creation of new markets and the disruption of existing industries. For this reason, they are particularly interesting objects of study for innovation management. This research investigates the creation of highly diffusable innovations in the contexts of the high uncertainty and open-endedness that prevails in most open innovation activities. Open innovation structures are proliferating, yet we still have only a rudimentary understanding of their ability to generate highly diffusible innovations. Through the analytical lens of collective bricolage, we examine how collective bricolage unfolds in open innovation and how it contributes to the creation of highly diffusable innovation. Our analysis builds on an in-depth empirical study of open innovation competitions in the semiconductor industry. The innovation contests provided a temporary open-ended structure that transformed individual participants into temporary team members who collectively explored opportunities for developing highly diffusable innovations. Based on an analysis of three generic technology innovation contests, we define a collective bricolage process for open-ended innovation consisting of four steps: a) pre-conditions, b) the repertoire, c) clustering, and d) prototyping. This model deepens our understanding of how collective bricolage, when undertaken in open innovation structures, produces highly diffusable innovations. This insight advances the literature on open innovation and, more generally, contributes to the field of innovation management.