Strain Sensors for Unbound Layers in Flexible Airport Pavements Using Pulsed Radar

This proposed details an innovative and powerful approach to measuring large-scale soil strain under pavement subjected to periodic loading. We propose to use Time-Modulated Ultra Wide Band (TM-UWB) impulse radar, in combination with a MEMS based passive sensor acting like a transponder embedded in the soil layer. The passive sensor is based on Surface Acoustic Wave (SAW) technology. Our proposed innovation allows for wireless and passive sensing of large scale strain (2000-20000 microstrain). The basic technology incorporated in the MEMS transponder was developed with the Center for Engineering of Electronic and Acoustic Materials (CEEAM) at Pennsylvania State University, a major source of innovation in the field of MEMS and smart sensors. For this proposal, IAI is collaborating with the CEEAM. IAI¿s extensive experience with pulsed radar application, and its unique relationship with a major innovator of pulsed radar equipment (Time Domain Corporation) mesh very well with the CEEAM¿s technological expertise. We envision applications in the automotive and biomedical fields, and in general market prospects are good for wireless sensors. In particular, the market for MEMS based devices, such as our innovation, is expected to grow at a compound annual growth rate of 6.3 percent through 2006.