It is often assumed that 'nano' is merely a communication and marketing token. Our inquiry in a number of French laboratories in the field of artificial molecular machines resulted in a quite different picture: a number of researchers are concerned with the definition of nanotechnology. This paper starts from the attempts made by one of the leading figure in the field of molecular machines, Christian Joachim, to draw a clear demarcation between what is 'really nano' and what is not. Probing the epistemological basis of his strategy, we also underline its limits. As this definition is only focused on the prefix 'nano', it would benefit from being completed and enlarged by a definition of 'technology'. We argue that molecular machines belong to the realm of technology in Gilbert Simondon's meaning of this term: a genesis of individualized objects coordinating natural processes and human projects. Finally, this emphasis on the technological dimension of nanotechnology leads to ethical reflections based on the practices of nanotechnology rather than on their potential applications.