1,721,287 research outputs found
Fluid Dispensing using Superparamagnetic Beads
No full textThe aim of this investigation is to produce an injection device for precise dispensing of nanolitre volumes of fluid using a piston formed from superparamagnetic beads. A plug of Fe2O3 beads is formed by applying a non-uniform magnetic field from a bullet magnet within close proximity to the fluid filled channel containing the beads. Once the plug is formed it can be moved through the micro channel by moving the magnet and thus, provide a plunger-like action. Fluid is displaced by moving the magnetic plug, providing a technique for fluid dispensing
Simulation studies of a β-SiC on insulator Pockels phase modulator
No full textWe have designed waveguide modulators using β-SiC-on-insulator waveguides and the Pockels effect. A 2D semiconductor device simulator was used to determine the electric field configuration in a double-Schottky diode structure. This allowed us to evaluate the local modulation of the refractive index as a function of applied external bias and to determine the effective index modulation of the guided mode. The optical simulations were performed using the Spectral Index and the Effective Index methods. Different 2D geometries are analyzed and the material parameters needed for fabricating such a device are determined. Application to Mach-Zehnder intensity modulators is described. Such devices have potential for high-speed Si-based photonic devices compatible with silicon technology
A superparamagnetic bead driven fluidic device
No full textInjection strategies have been employed in the field of fluidic MEMS using piezo electric or thermal actuators. A very popular application for such technology is inkjet printing. Largely this technology is used to produce droplets of fluid in air; the aim of this investigation is to produce an injection device for the precise dispensing of nanolitre volumes of fluid. A novel technique for dispensing fluid using superparamagnetic beads has been investigated. The beads used (Dynal Biotech) contain a homogeneous dispersion of Fe. This is an investigation using silicon and Pyrex fabricated micro channels with smaller dimensions, such that the dimensions will be similar to those which will be used to produce a pipette device. Here results are presented using these fabricated micro channels, where the effects of using differently sized bead plugs and varying velocities are examined. The results follow our proposed theory; further analysis is required to determine the operation of a bead plug during all states of movement
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