Magnetic nanowire-enhanced optomagnetic tweezers

We report an optomagnetic tweezers technique that utilizes the highly localized magnetic field gradients induced near the tip of a magnetic nanowire to provide strong trapping forces on magnetic nanoparticles with high spatial resolution. Integral to our approach is a method to trap, translate, and rotate a single magnetic nanowire in three dimensions. Our simulation predicts that forces in the range of 100 pN can be generated on 200 nm magnetic particles within 0.2 mu m from a 200 nm diameter nickel nanowire. Such forces are relevant in many biological processes, suggesting that this approach will be of value in biophysical studies.