Wireless Sensing Technologies for Infrastructure Assessment

The thrust of this proposal is to develop a compact integrated sensor/antenna that requires no power supply or wiring capable of addressing concerns of long term embedment/attachment. The proposed research is to employ wireless excitation and telemetry of sensor data from an array of SAW (Surface Acoustic Wave) sensors located on civil structures. These devices will be able to be attached to primary construction or power system components such as timber, steel, copper, concrete etc. The aim will be to develop a rugged sensor that is remotely interrogated. The measurements will be obtained through wireless remote access. A base station transmits a signal which is received by the antenna/sensor. This excites the sensor which then re-radiates a signal containing the raw sensor data back to the base station. An embbeded microprocessor in the base station then extracts the desired information. The sensor is completely passive, inexpensive, and reliable. As part of the research, we will also demonstrate that several measurements such as temperature, moisture content, normal stress, and shear stress can be simultaneously measured. We will investigate how this enables the removal of system changes for the measured data, such as, decoupling seasonal temperature change effects. The proposed system will have many applications for structural assessment permitting much more detailed, frequent, and inexpensive inspection of structures. This includes private sector buildings and plants as well as state and local structures, such as, bridges and utilities.