Abstract
Manipulation techniques are very important in biology research. Add to micro-nano technology fabrication to achieving on the research, the Lab-on-Chip for separating and focusing bioparticles is developed. Cell sorting or cell separation and focus are an important stage in biotechnology and biomedical processing which to extract or analytic form a mixture complex. The term AC electrokinetics refers to the movement of particles using AC electric fields. An AC electric field induces a frequency-dependent dipole on a polarizable particle. The interaction between the dipole and the non-uniform electric field is such that the particle experiences a force. This effect is called dielectrophoresis (DEP) which is the common method for the manipulation of bio-particles. In this thesis, we present a microsystem lab chip with high throughput continuous separation cell and particle characterization and focus via dielectrophoresis (DEP) and separation and focus particle based on size of particle. The particles are focus of hydrodynamic force by the design three inlets and will be deflected to separation and focus by control hydrodynamic drag and dielectrophoresis force. We design two electrode systems are separation electrode system and focus electrode system. The experiments are demonstrated with polystyrene (PS) beads 8 µm, 25µm and HepG2 cells (Human Liver cells) in suspension DEP buffer solution. Under a voltage 10 V peak-peak and frequency 100 kHz suitable, different characteristic particles have different DEP forces. Thus, the different distances of deflection that mean sample are separated. Then, the separated particle is focused for collection or optical detection application. Separation and focus based on size of particle is demonstrated on bead 8 µm and 15 µm.