This Small Business Technology Transfer (STTR) Phase I project addresses the need for relative humidity (RH) sensors that operate at high-temperature with good stability. The research objective of this project is the fabrication of composite RH sensors. The morphological stability mandated by the composite coupled with the documented excellent humidity response of the sensing material should result in enhanced durability and drift stability. Owing to the thermal stability of the composite sensing layer, these RH sensors should function at temperatures up to 300 C. If successful, the technology proposed will enable a new high temperature regime of RH sensing.<br/><br/>The composite materials science and engineering proposed is straightforward but innovative. If successfully developed, the research project proposed is quite amenable to large-scale production and will make a significant contribution in this field.