title: On-Chip Magnetic Platform for Single-Particle Manipulation with Integrated Electrical Feedback.
abstract: Methods for the manipulation of single magnetic particles have become very interesting, in particular for in vitro biological studies. Most of these studies require an external microscope to provide the operator with feedback for controlling the particle motion, thus preventing the use of magnetic particles in high-throughput experiments. In this paper, a simple and compact system with integrated electrical feedback is presented, implementing in the very same device both the manipulation and detection of the transit of single particles. The proposed platform is based on zig-zag shaped magnetic nanostructures, where transverse magnetic domain walls are pinned at the corners and attract magnetic particles in suspension. By applying suitable external magnetic fields, the domain walls move to the nearest corner, thus causing the step by step displacement of the particles along the nanostructure. The very same structure is also employed for detecting the bead transit. Indeed, the presence of the magnetic particle in suspension over the domain wall affects the depinning field required for its displacement. This characteristic field can be monitored through anisotropic magnetoresistance measurements, thus implementing an integrated electrical feedback of the bead transit. In particular, the individual manipulation and detection of single 1-μm sized beads is demonstrated.
authors.affiliation: Polifab center, Physics Department, Politecnico di Milano, Via G. Colombo n.81, 20133, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Monticelli
authors.affiliation: L-NESS center, Physics Department, Politecnico di Milano, Via Anzani n.42, 22100, Como, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Torti
authors.affiliation: Polifab center, Physics Department, Politecnico di Milano, Via G. Colombo n.81, 20133, Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cantoni
authors.affiliation: Polifab center, Physics Department, Politecnico di Milano, Via G. Colombo n.81, 20133, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Petti
authors.affiliation: Polifab center, Physics Department, Politecnico di Milano, Via G. Colombo n.81, 20133, Milan, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Albisetti
authors.affiliation: INRIM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce n. 91, 10135, Turin, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Manzin
authors.affiliation: L-NESS center, Physics Department, Politecnico di Milano, Via Anzani n.42, 22100, Como, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Guerriero
authors.affiliation: L-NESS center, Physics Department, Politecnico di Milano, Via Anzani n.42, 22100, Como, Italy.
authors.forename: Roman
authors.initials: R
authors.lastname: Sordan
authors.affiliation: Polifab center, Electronics Department, Politecnico di Milano, P.zza Leonardo da Vinci n.32, 20133, Milan, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Gervasoni
authors.affiliation: Polifab center, Electronics Department, Politecnico di Milano, P.zza Leonardo da Vinci n.32, 20133, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Carminati
authors.affiliation: Polifab center, Electronics Department, Politecnico di Milano, P.zza Leonardo da Vinci n.32, 20133, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ferrari
authors.affiliation: Polifab center, Electronics Department, Politecnico di Milano, P.zza Leonardo da Vinci n.32, 20133, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Sampietro
authors.affiliation: Polifab center, Physics Department, Politecnico di Milano, Via G. Colombo n.81, 20133, Milan, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bertacco
mesh_terms: D003198:Computer Simulation; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004560:Electricity; D005246:Feedback; D008280:Magnetics / Q000379:methods*; D008853:Microscopy
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon
keywords: anisotropic properties; lab-on-chip; magnetic beads; magnetic sensors; magnetic tweezers; magnetoresistance