Ion Images And Cell Sensor Based On Mems Technology

The biochemical sensor based on MEMS technology is developing quickly nowadays. It has the advantages of higher integration, higher sensitivity, less sample volume and lower cost. In thispaper, two microsensor arrays are studied------the ion image sensor array used for liquidcomponents analysis, and the Field Effect Transistor (FET) array used for detecting the active potential (AP) of living cell.The ion image micro sensors array can detect the pH value ranging from 1 to 12 and 6 kinds of metal ions, including Cu2*, Fe2+, Fe3+, Ca2+, Zn2+ and Mg2+ qualitatively and quantitatively. It combines the traditional titration method with microfabcrication technology. Also the idea of "array" is adopted, which can reduce the disadvantage of cross-sensitivity caused by the discrete selective sensor and has the advantages of significantly lower detection limit.In the experiments, we fabricate the microwells and microchannels on a P type silicon wafer with wet etching technology and deposite the microbeads with pH and metal indicators absorbed on the surface of them in the microwells. The image information under different solution samples is recorded in computer through microscope for further data processing and recognition. Moreover, three multivariate data analysis methods are suggested in the paper to treat the raw data, acquired from the microbeads, and to predict the results. The study demonstrates that the principal component analysis (PCA) is capable of classifying 6 kinds of cations with success, both Partial Least-Squares regression (PLS) and Artificial Neural Network (ANN) can be used to compute the pH value quantitatively and, furthermore, the PLS possesses the advantages of less iteration steps than ANN.In order to realize the auto sampling of the microsensor system, a micro pump is designed to integrated with the reaction chamber. The FEA (Finite Element Analysis) softwarepackage-----ANSYS is introduced to simulate the static, dynamic and fluid fields of the microdevice for optimizing the sensor system.The cell-based biosensor using FET array provides a non-invasive way for recording the active potention real time, and it can be reach to a single cell. The sensors array is designed and fabricated using traditional 1C technology. Poly-Left-Ornithine and Laminine are used as biological immobilization for inducing the growth of cardiac cells and the AP is measured underVthe treatment of the different drugs.Moreover, the ion image micro sensor array will be combined with the FET cell based sensor for studying the relationship between membrane potential and the influx /efflux of ions under the circumstance of outside stimulation and drug treatment. Then the mechanism of ion channels can be explored in order to investigate the application of this noninvasive measure system in the field of pathology analysis and drug screening.