Next Article in Journal
Target Localization in Wireless Sensor Networks Using Online Semi-Supervised Support Vector Regression
Next Article in Special Issue
A 3-Axis Miniature Magnetic Sensor Based on a Planar Fluxgate Magnetometer with an Orthogonal Fluxguide
Previous Article in Journal
Optical Detection of Paraoxon Using Single-Walled Carbon Nanotube Films with Attached Organophosphorus Hydrolase-Expressed Escherichia coli
Previous Article in Special Issue
Digital Control Analysis and Design of a Field-Sensed Magnetic Suspension System
Article Menu

Export Article

Open AccessArticle
Sensors 2015, 15(6), 12526-12538;

Strong Ferromagnetically-Coupled Spin Valve Sensor Devices for Droplet Magnetofluidics

Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany
Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainerstr. 70, 09107 Chemnitz, Germany
Author to whom correspondence should be addressed.
Academic Editor: Andreas Hütten
Received: 13 April 2015 / Accepted: 22 May 2015 / Published: 27 May 2015
(This article belongs to the Special Issue Magnetic Sensor Device-Part 1)
Full-Text   |   PDF [654 KB, uploaded 28 May 2015]   |  


We report a magnetofluidic device with integrated strong ferromagnetically-coupled and hysteresis-free spin valve sensors for dynamic monitoring of ferrofluid droplets in microfluidics. The strong ferromagnetic coupling between the free layer and the pinned layer of spin valve sensors is achieved by reducing the spacer thickness, while the hysteresis of the free layer is eliminated by the interplay between shape anisotropy and the strength of coupling. The increased ferromagnetic coupling field up to the remarkable 70 Oe, which is five-times larger than conventional solutions, brings key advantages for dynamic sensing, e.g., a larger biasing field giving rise to larger detection signals, facilitating the operation of devices without saturation of the sensors. Studies on the fundamental effects of an external magnetic field on the evolution of the shape of droplets, as enabled by the non-visual monitoring capability of the device, provides crucial information for future development of a magnetofluidic device for multiplexed assays. View Full-Text
Keywords: droplet microfluidics; spin valve; ferromagnetic coupling; high field sensing; ferrofluid droplet microfluidics; spin valve; ferromagnetic coupling; high field sensing; ferrofluid

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Lin, G.; Makarov, D.; Schmidt, O.G. Strong Ferromagnetically-Coupled Spin Valve Sensor Devices for Droplet Magnetofluidics. Sensors 2015, 15, 12526-12538.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top