The objective of this NASA Phase I SBIR program is to leverage lightweight, durable materials developed by NanoSonic for use within extra vehicular activity (EVA) space boots to provide the following benefits: weight reduction, increased durability/longevity and thermal protection/comfort. NanoSonic will collaborate with ILC Dover, the manufacturer of the EVA space boot, to develop next-generation designs employing the adaptive thermal control materials described herein. Next-generation designs will increase the comfort and productivity while reducing fatigue and injury risks provided to crew members. Further, these next-generation EVA boot materials shall also provide enhanced instep support and enable better boot sizing as indexing. To address the comfort and thermal concerns within the EVA boot, NanoSonic will work with ILC Dover, the world's leader in EVA spacesuits, who was recently awarded the contract by NASA to develop the Z-2 advanced spacesuit. In addition to providing enhancements for foot indexing and thermal comfort, NanoSonic will work with ILC to ensure that the solutions developed herein provide weight savings and increased durability such that the EVA prototype boots developed in the Phase II effort will afford crew members increased comfort and productivity while reducing fatigue and injury risk. The proposed program would start at TRL 5 and end at TRL 8 after a Phase II effort.