Papers by Author: L.Q. Du

Abstract: Micro hot embossing mold of microfluidic chip used in flow cytometry is designed and microfabricated. After some kinds of microfabrication processes are tried, this paper presents a novel microfabrication technology of micro hot embossing metal mold. Micro metal mold is fabricated by low-cost UV-LIGA surface micro fabrication process using negative thick photoresist, SU-8. Different from other micro hot embossing molds, the micro mold with vertical sidewalls is fabricated by micro nickel electroforming directly on Nickel base. Based on the micro Nickel mold and automation fabrication system, high precision and mass-producing microfluidic chips have been fabricated and they have been used in flow cytometry

Abstract: Piezoelectric bimorph fabricated by hydrothermal method is presented in the paper. This method is low cost, simple and easy. In order to describe the characteristics of piezoelectric bimorph, properties of PZT film are studied by XRD and SEM. The ratio of PbTiO3/PbZrO3 in PZT is 53/47, which is around morphotropic phase boundary (MPB). PZT film is composed of cubic particles with the average size of 5μm. Density is figured out through the datum measured in experiments. The model used to analyze the driving ability of bimorph is set up; piezoelectric coefficient d31 of PZT film is worked out using this model. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph Vc =1.67V is obtained.