Structures magnétiques et micro-systèmes pour applications biologiques

摘要: The range of applications for magnetic micro- and nano-particles is constantlyexpanding, in particular medicine biology. A number involve particletrapping deviation under the effect a field gradient. In mostpublications, required fields are produced either using soft elementspolarized by an external field, electromagnets or bulk permanent magnets.Micromagnets produce high favor autonomy stability while downscalingleads to increase gradients. challenge good quality, hardmagnetic films 1 100 μm both thickness lateral dimensions tointegrate them into Bio-Mag-MEMS.Physical vapor deposition (triode sputtering) used prepare quality rare earthmagnets thick film form. order obtain gradients directions, threetechniques have been developed:• Topographic patterning, which itself patterned sputtering ontopre-etched substrates etching film.• Thermo-magnetic exploits temperature dependance coercivityto locally reorient magnetization.• Micro imprinting, consists organizing powder with aidof above-cited magnets, then embedding polymeric matrix.Such micro-magnets autonomous, having no requirements cumbersome externalfield source nor power supply.Here we demonstrate potential develop autonomous devices based on micromagnetarrays. Controlled positioning superparamagnetic particles as model shown at first.Then, magnet arrays study endocytic processes magnetically labelledbiological elements.In step towards device integration, microfluidic channels above themagnet arrays. Magnetic non-magnetic pumped through andprecise positioning, well guiding sorting performed. High purity obtained inthe sorted solutions.The results development micromagnetic flux sources, integrationinto microdevices particle/cell handling indicate thiswork actual biological medical applications. Moreover, biocompatibility andautonomy such allow their use micro-total-analysis systems, point-of-care orimplantable devices.