Microfluidic Devices Based On Electrowetting Effect On The Media Figures

With the scaling down of MEMS device,interfacial tension as an inherently dominant force on micrometer and nanometer scale has attracted increasing serious attention.EWOD(Electrowetting on dielectric) micro-fluidics using interfacial tension as driving force emerges in recent years.Its high operating voltage and poor IC compatibility block its spreading application in Lab-on-a-chip.A novel single-side coplanar electrode array EWOD digital microfluidics is developed,with a high K dielectric material and a novel device structure.The operating voltage of the device is lowered effectively,and its fabrication process is compatible with IC as well.The theory of surface tension actuation is studied and its dependence on the surface modification is discussed.Based on the EWOD theory and experiments results,an organic ferroelectric material P(VDF-TrFE) with high dielectric constant(K=7.6-11.6) is selected as the dielectric layer.The contact angle of droplet changes from 118°to 75°under an applied voltage of 30V,which can be applied for droplet driving.EWOD of microfluidics using P(VDF-TrFE) is studied.A voltage-polarity-related EWOD phenomenon is observed.To put this phenomenon into application,the diving voltage of the device can be decreased to 15V.Based on voltage-polarity-related EWOD phenomenon,a novel single-side coplanar electrodes array digital microfluidics is designed and fabricated.A droplet of 3uL PBS is successfully driven back and forth on the planar surface under an operating voltage of 20V.The peripheral controlling platforms are also designed and fabricated,droplets can be driven automatically.