The Department of Health and Human Services, specifically the National Institutes of Health, is seeking proposals for the development of tools for decentralized clinical trials (DCT) for substance use disorder (SUD). The traditional approach to SUD clinical trials involves in-person visits at clinical trial sites, which can limit participation and retention due to factors such as travel time, stigma, and caregiving responsibilities. DCTs offer a solution by utilizing telehealth visits, remote monitoring, and local medication dispensing. However, there are gaps in the existing technology, such as the lack of wearable sensors for physiological measurement and home-use detection devices for quantifying substances of interest. Additionally, there is a need for a comprehensive system that facilitates data movement and communication with study participants. The research questions in this solicitation focus on the development of wearable devices, socially acceptable devices for SUD trials, software solutions for data handling, and systems capable of operating in low-bandwidth or rural areas. The Small Business Technology Transfer (STTR) program is offering Phase I and Fast Track funding opportunities to support the technical merit, feasibility, and commercial potential of the proposed research and development efforts. Successful projects are expected to attract strategic partners or investors for further commercialization.