We aim to study the interplay among formal and informal channels of university-industry knowledge transfer (UIKT) through time. To do so, we adopt two different methodologies. In the first one we resort to a cross section analysis based on a survey of French academic researchers to capture the correlation between these activities in a static setting. To capture the dynamics of these interactions, we complement it with a longitudinal and qualitative interview data analysis allowing us to observe the remarkable research and technology transfer trajectories of two reputable researchers in the fields of robotics and pharmacy. First findings suggest that formal and informal UIKT activities are highly interdependent and mutually reinforcing. The multiplication of transfer activities, flow and the capitalization of knowledge in academic teams over time lead therefore to new combinations of knowledge across different research thematic and open the door to further possible technology transfer activities. This suggests that there is not only one single pattern of interaction among UIKT channels but many different ones. The longitudinal approach shows the critical role played by the social networks of researchers in the success of technology transfer projects, suggesting that technology transfer offices of universities can play wider role than managing intellectual property. The cases also reveal the important role of PhD students or post-docs to accompany the technology transfer from academic research to firms or to create start-ups. Depending the technological fields considered, the interaction between formal and informal technology transfer channels are not the same, but in each case the patent plays an important role and make the technology transfer possible. The patent protects the inventions and constitutes a tangible proof of credibility for potential partners or funders. However, the role it plays is not the same in the two cases studied. Depending on the nature of the technology and the importance of tacit knowledge, the actors adopt different strategies to protect intellectual property.
