Knowledge transfer from biologists to engineers is one of the main obstacles to the diffusion of Biomimetic. An approach to overcome this obsta-cle is presented and discussed. This approach is based on a construct to describe high-level engi-neering functions stored in a relational data-base to-gether with a species grouping based on a functional classification, the corresponding biological solutions and the "official" taxonomy. Several relationships among the keys allow extracting and organizing the stored knowledge both from the engineering and from the biological point of view. Trough this data-base, an engineer can extract all the biological solutions of a function formulated in the "engineer's language", and then determine the more suitable solution for his/her specific problem. KEYWORDS Biomimetic, biological knowledge in engineering science, engineering knowledge in biology, bi-directional knowledge transfer, relational data-base, functional description, principles and solutions de-scription