40 research outputs found
Simulation of magnetic active polymers for versatile microfluidic devices
We propose to use a compound of magnetic nanoparticles (20-100 nm) embedded
in a flexible polymer (Polydimethylsiloxane PDMS) to filter circulating tumor
cells (CTCs). The analysis of CTCs is an emerging tool for cancer biology
research and clinical cancer management including the detection, diagnosis and
monitoring of cancer. The combination of experiments and simulations lead to a
versatile microfluidic lab-on-chip device. Simulations are essential to
understand the influence of the embedded nanoparticles in the elastic PDMS when
applying a magnetic gradient field. It combines finite element calculations of
the polymer, magnetic simulations of the embedded nanoparticles and the fluid
dynamic calculations of blood plasma and blood cells. With the use of magnetic
active polymers a wide range of tunable microfluidic structures can be created.
The method can help to increase the yield of needed isolated CTCs
Microstructure Role in Permanent Magnet Eddy Current Losses
The impact of granular microstructure in permanent magnets on eddy current
losses are investigated. A numerical homogenization procedure for electrical
conductivity is defined. Then, an approximated simple analytical model for the
homogenized conductivity able to capture the main features of the geometrical
and material dependences is derived. Finally eddy current losses analytical
calculations are given, and the two asymptotic expressions for losses in the
stationary conduction limit and advanced skin effect limit are derived and
discussed.Comment: 5 pages, 7 figure