Thermal Gradient Driven Digital-droplet-transporting-chip

摘要

In this paper,a droplet transporting chip induced by thermal gradient has been designed, fabricated and characterized. The digital microfluidic chip with Ti as micro-heater, Au film as pad, PECVD SiO2 as dielectric layer on glass substrate, is fabricated by the silicon bulk process, employing fluorocarbon polymer to functionalize the surface to be hydrophobic to facilitate droplet transportation. The simulation results from ANSYS show that the maximum temperature of micro-resistive heater can reach 368K with the maximum thermal gradient of 38 o /mm in power of 0.5W at 300K. Experiment results show that DI water and silicon oil can be transported on device surface smoothly. The driving voltage is less than 10V for 3 l μdeionized (DI) water, while it is 5V for silicon oil, and the transport speed can reach 0.1mm/s and 1mm/s in the power of 0.38W, respectively. The digital-droplet-transporting-chip can be found applications in lab on a chip due to its simple structure and low-cost fabrication process.