TABLE OF CONTENTS MAGMAS (magnetic micro-actuators & systems) are an emerging family of MEMS (micro electromechanical systems) and MOEMS (Optical MEMS). They should experience an important growth within the next few years in the same way as MEMS and MOEMS did since the late 1980's [BUS 92]. Magnetically actuated miniature and micro-motors, -generators, -pumps, -switches, -relays, -scanners etc, offer potential applications within the IT, bio-medical, spatial and automotive fields. MAGMAS exploit magnetic interactions between magnets, coils and other magnetic materials. These materials and the elaboration techniques are currently developing very fast and thus MAGMAS now exhibit high power-to-mass performances as well as good efficiency, in comparison with electrostatic and piezoelectric counterparts.
The key actors of such performances are chiefly the high energy product rare-earth permanent magnets, combined with high current densities flowing through integrated micro-coils. Emphasis must be directed towards the elaboration of REPM thick films, and particularly on compatibility with the established MEMS micro-technology processes (thermal, chemical, substrate size etc). This contribution presents a review of the state of the art in miniature permanent magnets and their elaboration techniques, as well as a rapid panorama of MAGMAS and their potential applications.
A book dedicated to MAGMAS is currently under press at Herm s/Lavoisier, within the EGEM series (in French) [CUG 02]. This book is coordinated by the author, and co-written by several partners. Its eleven chapters cover all topics about magnetic micro-actuators, starting with three chapters describing electro-magnetic interactions and their scale reduction laws.
