Mazhar ul Hogue
 

Title: M.S. candidate in Electrical Engineering Advisor: Dr. Abdulkader Tayebi Topic: Feasibility Study of Embeded MEMS Strain Sensors in Polymers for Infrastructure Rehabilitation

Most difficult part of optimal strain transfer is related to the high modulus of silicon embedded in a low modulus matrix. Studies of load transfer mechanism of short fiber composite showed that critical strain transfer lengths can be related to the modulus of the materials and geometry of the sensor. Different types of strain sensors will be assumed to be embedded inside a composite structure. Different types of load will be applied on the composite with embedded strain sensor in it and its response will be monitored using ANSYS. Different materials will be used for the geometric structure of the strain sensors to see which one offers the best strain transfer from the composite to the sensor. The geometric shape of the sensor can also be modified to have better strain transfer. An embedded sensor system consists of a sensor, signal processing circuit and an antenna. So while modeling the effect of external loading on the embedded strain sensor, the circuit chip and the antenna should also be included in the modeling. Because they will have an effect on the strain field that will be detected by the sensor. To include the effect of the signal processing circuit and the antenna, these two elements can also be modeled along with the sensor. They can be considered to be a lumped solid element (rectangular or circular) just beside the sensor itself on the same wafer. So using ANSYS, a reliable strain sensor can be proposed that can be used to measure the strain inside the composite materials. The optimal geometric shape of the sensor can also be obtained along with the type of material to be used for the sensor to ensure maximum strain transfer from the composite material. Along with the reliability testing of the different types of strain sensors with different materials for different parts of it, the optimum position of the embedded sensors inside the material can also be modeled. This will provide the minimum distance among the sensors that will ensure the availability of the structural information of maximum portion of the composite material.