LTCC 3D MICROMIXERS FOR NON-MISCIBLE FLUIDS MICROEMULSION GENERATION

Abstract

Abstract The present work shows a ceramics microfluidic device for non-miscible fluids microemulsion generation using 3D serpentine micromixers. The technology used for device fabrication was Low Temperature Cofired Ceramics (LTCC) which allows us for complex, high temperature and pressure resistant 3D microfluidic devices. The proposed device aims to obtain microemulsion with controlled drop size, low dispersion index and high production volumes using Top-Down approach. Previous simulation work had showed 3D serpentine as one of the best structures for rapid mixing due the chaotic advection generated on every 90 deg direction change. This effect, when mixing two fluids as oil and water leads to streamlines pinching-off making possible drop generation. We have used this effect on our device. For the experimental section, it was fabricated a 3D serpentine mixer microfluidic device with working region suitable for variable total flow rate. For certain value of total flow rate, the microemulsion showed higher drop diameter and polydispersity values. In this region, no control could be done in order to obtain the same drop value with the same process parameters. Inside the working region drop diameter values repeatability was obtained. In this region our experimental results had showed a relation between drop diameter and total flow rate. As a total flow rate increase the drop diameter decrease due to a stronger chaotic advection effect. In the other hand, the polydispersity index also decreases. Microemulsions with average size lower than few micrometer or submicron were obtained. When compared with other reported devices, our device presented a production volume in the range of tens of ml/s for the same output microemulsion size.