Magneto-electrical orientation of lipid-coated graphitic micro-particles in solution in RSC Advances (April 2016). By J. Nguyen, S. Contera, and I. Llorente García.
This paper presents a novel method for manipulating anisotropic, lipid coated- biocompatible graphitic micro-particles in aqueous solution. The method is based on the application of two perpendicular fields: a vertical static magnetic field and a horizontal time-varying electric field oscillating at fast frequencies (MHz). We generate rotational traps to confine the orientation of the micro-particles parallel to the plane containing both fields and use measurements of random orientational fluctuations of the particles due to collisions with water molecules to calibrate the strength of the traps and measure the torque exerted on them, as well as to measure their dependence on the frequency of the applied electric field.
Our new method enables quantification of the response of the micro-particles to orienting fields in different experimental configurations for a broad range of applications. These include energy storage devices, opto-electronic devices, synthesis of artificial materials, biological and chemical sensing applications, fundamental studies in biological and medical physics, etc. Our scheme can be applied to other carbon-based micro/nano-particles, such as graphene platelets or carbon-nanotubes, has great potential for being scaled down via micro-fabrication, and can open up new ways for trapping, transporting and separating these particles with the use of time-varying fields enabling frequency-control of the magneto-electrical manipulations.
This work is in collaboration with Prof. Sonia Contera from Oxford Physics.