Basic Theory And Key Technique Research Of Low Voltage, High Throughput MEMS Digital Microfluidics Chip

Recently, Lab-on-a-chip technology has become one of most important field of miniaturized analytical instruments on the basis of the development of miniaturized total analytical system. Capable of manipulating droplets of volume from microliter to picoliter in a flexible and speed way, electrowetting based digital microfluidics technologies have been widely explored for biological and chemical detections to archive the “Lab-on-a-chip” targets.However, some difficulties still remain in eletrowetting based digital microfluidics, such as high driving voltage, dynamic saturation and lack of devices for high-throughput analysis, and so on. This magisterial thesis develops a low voltage, high-throughput electrowetting based actuator design. Theoretical analysis and experiments have carried out to demonstrate the device, including low voltage, improved digital dynamics, and capability for high-throughput analysis. The relationship between dynamic saturation and device physics is talked about based a novel dynamic model developed here. Furthermore, electrowetting based digital microfluidic chip integrating with piezoelectric MEMS sensor is demonstrated.The main investigations in this thesis are as the following.(1) On the basis of a large reference and previous work, the design and evaluation methods of digital microfluidic chip have been proposed, based on which a low voltage and high-throughput electrowetting actuator is demonstrated.(2) The digital microfluidic chip fabrication using MEMS fabricating technology is carried out, and dynamic experiments of the proposed device has been done. By comparing with different conventional electrowetting actuators, the improved properties of this novel device is obtained.(3) The dynamic saturation effect of droplet motion in digital microfluidic systems has been explained by a new developed dynamic model, based on which the relationship between dynamics of electrowetting droplet motion and device physics have been discussed.(4) The integration process of digital microfluidic chip and piezoelectric sensor is explored, and a high-throughput digital microfluidic chip of low voltage, improved dynamic properties is demonstrated suitable for biochemical detections.