The last few years have revealed a surprising self-organising ability of adult and embryonic stem cells. This ability is different from that of traditional physical systems as it has an underlying genetic basis and, in manners that we don’t understand, depends on the starting conditions. Looking at what these cells do in vivo and ex vivo makes us think more of ‘self-engineering’ than ‘self-organisation” a process in which a set of instructions and programs unfolds and produces tissues and organs. Understanding these processes will yield not only new insights into biological systems but also, in mastering this self-engineering, we shall open up new possibilities for biomedical research. This task requires an interaction between stem cell and developmental biologists with engineers and physicists. This meeting, the third of its kind, aims to bring these constituencies together to explore ideas and technical developments that can shape this new field.