The living lab methodology is an approach to realise the innovation process by bringing together users, technology and business for collective ideation in a real-life environment. This study looked into the human level of the boundary-spanning activities within a living lab group via a case study on a university living lab of medical devices. This research aimed to provide insights on the interpersonal interaction to optimise the mutual learning between participants of a university living lab. The results of this research were translated into a communication tool to realise the optimal mutual learning within a living lab context. This research found out that the identification process played an important role in facilitating users to obtain benefits of the boundary-spanning activities while mitigating the possibility of conflicts. In the process of dynamic formation of professional identity in a living lab context, various identities of competence come closer and intersect with each other. The supervenient overlapping area of different competence can be regarded as the identity of knowledgeability. Knowledgeability manifests the ability to see the relevance of other competence to a professional’s own competence. Translated into practice in the design process of medical devices, the identity of competence provides a feasibility scope of expertise, which makes sure the design decision would be viable in the future commercialisation according to a certain aspect. Actors with knowledgeability to all the expertise in a group can better tweak the decision into the overlapping area of all the feasibility scopes of expertise, for example, of clinical, engineering and commercial expertise in this case. This research suggests that knowledgeability could be an indicator of so-called boundary-spanning competence. Knowledgeability is the result of identification in the interdisciplinary interaction within a living lab context. When designing a tool to facilitate the acquisition of knowledgeability, this study utilised the three modes of identification, namely imagination, engagement and alignment as the foundation of the tool. The tool stimulates reflection of the users through a series of inspiring questions and guides the users to reap the benefits of daily interdisciplinary conversations through communicative solutions. The main recommendations for future research entail taking this preliminary tool as a starting point to explore the cognitive activities further when people engage in boundary-spanning activities and the psychological aspect of the identification process. Furthermore, defining the quantitative criteria of knowledgeability would greatly improve the reliability and usefulness of the tool.