| Self-assembled monolayers(SAMs)are two-dimensional assemblies formed by the adsorption of organic molecular constituents from solution or gas phase onto the surface of solids,and the unique electrical property of the SAMs have attracted wide attention.SAMs have thickness close to the molecular length,that the electrical properties of SAMs represent the tunneling of the molecular constituents.For the electrical measurement of SAMs,the conducting metal that a SAM formed on can act as one electrode.There are a variety of conducting materials can be used as another electrode,including eutectic gallium-indium(EGaln)is one of them.The application of EGaIn in electrical measurements of SAMs has attracted widespread attention due to its low short rate and easy to perform.But the shape of EGaIn electrodes usually is conical tip,and the preparation and movement of the electrode often performed by a handwork micromanipulator,leading to the disadvantage is the high requirements of the experience in operation,and the repeatability is difficult to ensure.In this thesis,we designed and developed the auto-control system for the electrical measurement of SAMs using EGaIn electrode,then the experimental method and control parameters of the system was discussed.The content of this thesis are listed as follows:1.Design and built a mobile platform with three degrees of freedom,cooperate along witn a home-made current measurement system,comprises the EGaIn-SAM testing system,achieved control accuracy of micron order and pA measurement.2.Develop programs for mobile platform control and current data acquisition using National Instrument data acquisition card and LabVIEW software.A Matlab program package was written for automatic data processing.3.The impact of shape and hanging time of the EGaIn electrode were measured to analysis the oxide layer and water layer of EGaIn electrode.And explorer the parameterization of the EGaIn-SAM testing. |
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