A new type of functionalized magnetic nanoparticles is developed, consisting in micro- nanomagnetic tweezers, attached to the substrate or released in solution, for biomedical applications.
SPINTEC : Nanomagnetism integrated in microtechnology
INAC/SPrAM/CREAB : Functionalization, biotechnological applications.
LTM (CNRS) : Microfluidics
ANR (National Research Agency) supporting the Project P2N NANO-SHARK, ref ANR-11-NANO–001.
Allocation doctorat de l’Ecole Doctorale de physique de Grenoble
The aim is to develop a new type of functionalized magnetic nanoparticles, such as “jaws” or tweezers, actuated by an applied magnetic field. A first step is the technological development of the tweezers and the demonstration of their opening/closing controlled by the field. Then the demonstration of specific molecules or biological objects catching, the functionalized tweezers remaining attached to the substrate. Next biological gels grabbing, and microtweezers sorting will be performed with tweezers in suspension in a solution. A microfluidic system will be intended to study the hydrodynamic and magnetophoretic properties of the nano-objects, behaving as nanorobots in solution. The potential applications are numerous especially in the field of biotechnology and biomedical applications.
First experimental realizations and tests of this technology of deformable particles have been obtained, comprising the fabrication of two mobile magnetic elements bound by a hinge. The proposed technology of fabrication relies on a “top-down” approach, involving the following steps :
1) patterning of an array of micronic resist dots by lithography or nanoimprint (SPINTEC, LTM),
2) deposition of specific magnetic materials based on SPINTEC knowledge from spintronic studies (SPINTEC),
3) deposition of the sacrificial layer between the two mobile parts of the tweezers, coating by biocompatible materials (Au, SiO2), deposition of the hinge material at oblique incidence (SPINTEC),
4) dissolution of the sacrificial layer thus releasing one part of the tweezers with respect to the other (SPINTEC, SPRAM),
5) (optional) functionalization of the inner part of the tweezers (SPRAM),
6) (optional) lift-off of the magnetic tweezers in solution (SPINTEC).
 “Self-polarization phenomenon and control of dispersion of synthetic antiferromagnetic nanoparticules for biological applications”, H. Joisten, T. Courcier, P. Balint, P. Sabon, S. Auffret, J. Faure-Vincent, and B. Dieny, Appl. Phys. Lett. 97, 253112 , (2010).
”Tumbling motion yielding fast displacements of synthetic antiferromagnetic nanoparticles for biological applications” ,T. Courcier, H. Joisten, P. Sabon, S. Leulmi, T. Dietsch, J. Faure-Vincent, S. Auffret, B. Dieny, Appl. Phys. Lett. 99, 093107 (2011).
 “High-Moment Antiferromagnetic Nanoparticles with Tunable Magnetic Properties”, Wei Hu, R. J. Wilson, A. Koh, A. Fu, A. Z. Faranesh, C. M. Earhart, S. J. Osterfeld, S.-J. Han, L. Xu, S. Guccione, R. Sinclair, & S. X. Wang, Stanford Univ., USA, Adv. Materials, 1479-1483, (2008)
“MICROSCALE OR NANOSCALE MAGNETIC TWEEZERS AND PROCESS FOR FABRICATING SUCH TWEEZERS”, B. Dieny, P. Sabon, H. Joisten, WO201217024 ; FR2963615 ; (2010).
“MAGNETIC MICROPARTICLE AND METHOD FOR MAKING SUCH A MICROPARTICLE”, B. Dieny, H. Joisten, P. Sabon, WO2011033080, FR2950042, (2009)
“METHOD FOR MANUFACTURING PARTICLES SUCH AS MAGNETIC MICRO- OR NANOPARTICLES”, B. Dieny, P. Sabon, J. Faure-Vincent