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Study On Novel Single Planar Digital Microfluidic Device And Application In Lab-on-chip

Posted on:2015-05-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:X Y CengFull Text:PDF
GTID:1108330464955666Subject:Microelectronics and Solid State Electronics
Abstract/Summary:PDF Full Text Request
Lab-on-chip (LOC) based on microfluidic has great application value in the field of biology, chemistry, medicine and clinical diagnosis. In recent years, Electro-Wetting-on-Dielectric (EWOD) digital microfluidic chip for controlling of reagent droplets has become a hot spot in the field of LOC due to many advantages. For examples, it can reduce the reagents and sample consumption and has no dead volume and contamination. Meanwhile, it has flexible manipulation on droplets and is easy to realize automation and portable detection. As a novel structure of EWOD chips, the single planar structure overcomes many disadvantages of traditional’sandwich’ structure, sush as complicated structure, large movement resistance of droplet, difficulty in injecting droplets and integration. Thus, it is the core device in the integrated biochemical LOC detection system.This dissertation focuses on the research of EWOD based novel single planar transparent microfluidic device and its application in the LOC optical detection system. Firstly, three novel single planar transparent EWOD digital microfluidic chips based on three different principles are proposed. Secondly, the driving ability of the single polar single planar transparent EWOD chip based on the coupling ground principle is optimized. The driving voltage of the droplet is reduced. Thirdly, combining with the chemiluminescence detection technology, the biochemical LOC detection system is built up which integrates the single polar single planar transparent EWOD chip with the photodetector. Fourthly, the detection of the concentration of H2O2 and glucose is realized in the LOC detection system. Finally, by investigating the reliability problem of the LOC detection system, an on-chip integrated heater is designed and an on-chip recoverable chemiluminescence LOC detection system is realized.The major innovation of this dissertation includes the following three parts:1. A single polar single planar transparent EWOD digital microfluidic device is proposed, which is based on the coupling ground principle. It has a simple structure and outstanding performance in controlling droplets. The droplet moves with the speed of 40mm/s under the low driving voltage of 24V.2. A miniaturized LOC detection system is built up, which combines the single polar single planar transparent EWOD chip with a photodetector. It is applied in chemiluminescence detection. The system takes the advantage of the light focusing ability of the single planar device. It reaches a large linear range (1μM-20mM) for the detection of glucose.3. The mechanism of the surface hydrophobic failure of the EWOD chip in chemiluminescence detection is investigated. It is found that the main cause of the failure is attributed to the C-F bond breakage and the C-O bond formation. A method to recover the surface back to hydrophobization is proposed accordingly. An integrated heater is designed and manufactured to fully recover the hydrophobicity of the surface by annealing at 900mW for 5min.
Keywords/Search Tags:EWOD(Electro-Wetting-on-Dielectric), digital microfluidic chip, lab- on-chip, coupling ground, integrated heater
PDF Full Text Request
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