A novel vertical actuator based on electrowetting on dielectric （EWOD） was designed, analyzed and simulated. Modeling results indicated that the vertical driving force of the actuator obeyed a second order polynomia...A novel vertical actuator based on electrowetting on dielectric （EWOD） was designed, analyzed and simulated. Modeling results indicated that the vertical driving force of the actuator obeyed a second order polynomial of applied voltage, which was verified by Covent_ware 2006. As a resuit, the vertical driving force of the EWOD actuator with a 1.1 nL droplet and a 1.75 μm thick polymer was about 0.5 μN under an applied voltage 100V which was comparable to that of the electrostatic actuators. Moreover, the noise from plane forces we analyzed and simulated was very low. Therefore, we made a conclusion that the EWOD actuator can be used in MEMS transducer.展开更多
Electrowetting-on-dielectric (EWOD) is to directly control the wettability of liquids on the solid surface by applying the electric potential to the microelectrode array under the dielectric layer. The prototype of th...Electrowetting-on-dielectric (EWOD) is to directly control the wettability of liquids on the solid surface by applying the electric potential to the microelectrode array under the dielectric layer. The prototype of the EWOD droplet creator with the sandwiched structure is used: the droplet is sandwiched between the top and bottom plates; the bot- tom plate consists of silicon used as the substrate of the microelectrode array, nitride sili- con film deposited by low pressure chemical vapor deposition as the dielectric layer and the fluorocarbon polymer film deposited by inductively coupled plasma chemical vapor deposition as the hydrophobic layer; and the top plate is the transparent electrode covered with the hydrophobic layer. To obtain the required minimum voltage, the process and the criterion of creating droplets are analyzed. At the voltage of 35 V the deionized water droplet surrounded in silicone oil is successfully created.展开更多
A droplet-based actuating chip by using the method of electrowetting-on-dielectric(EWOD)was developed to manipulate the microfluidics.Here,the actuation mechanism of the sandwiched-configuration EWOD chips was careful...A droplet-based actuating chip by using the method of electrowetting-on-dielectric(EWOD)was developed to manipulate the microfluidics.Here,the actuation mechanism of the sandwiched-configuration EWOD chips was carefully studied,and the movement of droplets was numerically analyzed by using the computational fluidic software,CFD-ACE+.The fabrication of the chip,including a heavily phosphorus-doped poly-silicon micro-electrode array and a thermally grown SiO2 dielectric layer,was exploited to improve the chip stability and decrease the actuation voltage.In experiments,the transportation of a deionized droplet of about 0.5μL is successfully achieved in air by applying the low voltage of 45 V.展开更多
研究了单平面透明介质上的电润湿(Electrowetting on Dielectrics,EWOD)数字微流体器件在化学发光检测器中的两个可靠性问题.一是通过对介质层的研究,使用PVD制备300nm Ta_2O_5介质层使驱动电压降低至20.7V,在驱动电压26.9V下速度达到40...研究了单平面透明介质上的电润湿(Electrowetting on Dielectrics,EWOD)数字微流体器件在化学发光检测器中的两个可靠性问题.一是通过对介质层的研究,使用PVD制备300nm Ta_2O_5介质层使驱动电压降低至20.7V,在驱动电压26.9V下速度达到40mm/s;二是通过设置片上加热器解决了Teflon的失效问题,使用1W功率加热5min实现片上疏水角恢复至120°.集成嵌入式加热器的EWOD器件用于葡萄糖检测时,最高灵敏度达到0.12V/(μmol·L^(-1)),检测范围1~20 000μmol/L,最低检测限为1μmol/L.展开更多
文摘A novel vertical actuator based on electrowetting on dielectric （EWOD） was designed, analyzed and simulated. Modeling results indicated that the vertical driving force of the actuator obeyed a second order polynomial of applied voltage, which was verified by Covent_ware 2006. As a resuit, the vertical driving force of the EWOD actuator with a 1.1 nL droplet and a 1.75 μm thick polymer was about 0.5 μN under an applied voltage 100V which was comparable to that of the electrostatic actuators. Moreover, the noise from plane forces we analyzed and simulated was very low. Therefore, we made a conclusion that the EWOD actuator can be used in MEMS transducer.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 10472055 and 60411009), the Fundamental Research Foundation of Tsinghua University (Grant Nos. JC2003060 and JC2003061).
文摘Electrowetting-on-dielectric (EWOD) is to directly control the wettability of liquids on the solid surface by applying the electric potential to the microelectrode array under the dielectric layer. The prototype of the EWOD droplet creator with the sandwiched structure is used: the droplet is sandwiched between the top and bottom plates; the bot- tom plate consists of silicon used as the substrate of the microelectrode array, nitride sili- con film deposited by low pressure chemical vapor deposition as the dielectric layer and the fluorocarbon polymer film deposited by inductively coupled plasma chemical vapor deposition as the hydrophobic layer; and the top plate is the transparent electrode covered with the hydrophobic layer. To obtain the required minimum voltage, the process and the criterion of creating droplets are analyzed. At the voltage of 35 V the deionized water droplet surrounded in silicone oil is successfully created.
基金supported by the National Natural Science Foundation of China (Grant No.10472055)the Fundamental Research Foundation of Tsinghua University (No.JC2003060).
文摘A droplet-based actuating chip by using the method of electrowetting-on-dielectric(EWOD)was developed to manipulate the microfluidics.Here,the actuation mechanism of the sandwiched-configuration EWOD chips was carefully studied,and the movement of droplets was numerically analyzed by using the computational fluidic software,CFD-ACE+.The fabrication of the chip,including a heavily phosphorus-doped poly-silicon micro-electrode array and a thermally grown SiO2 dielectric layer,was exploited to improve the chip stability and decrease the actuation voltage.In experiments,the transportation of a deionized droplet of about 0.5μL is successfully achieved in air by applying the low voltage of 45 V.
文摘研究了单平面透明介质上的电润湿(Electrowetting on Dielectrics,EWOD)数字微流体器件在化学发光检测器中的两个可靠性问题.一是通过对介质层的研究,使用PVD制备300nm Ta_2O_5介质层使驱动电压降低至20.7V,在驱动电压26.9V下速度达到40mm/s;二是通过设置片上加热器解决了Teflon的失效问题,使用1W功率加热5min实现片上疏水角恢复至120°.集成嵌入式加热器的EWOD器件用于葡萄糖检测时,最高灵敏度达到0.12V/(μmol·L^(-1)),检测范围1~20 000μmol/L,最低检测限为1μmol/L.
