The Nanoscale Interactions program, part of the National Science Foundation's Engineering Directorate, seeks to support fundamental and quantitative research on the interactions of nanomaterials and nanosystems with biological and environmental media. Key focus areas include characterization of nanomaterial interfaces, development of predictive tools for nanomaterial processing and engineering, examination of nanomaterial transport and impact, and computational modeling of nanoparticle behavior. Collaborative and interdisciplinary proposals are encouraged. Proposals should address the novelty and transformative potential of the research, as well as its impact on engineering science and society/industry. The program accepts unsolicited proposals, with typical single-investigator awards providing support for one graduate student and up to one month of PI time per year. Faculty Early Career Development (CAREER) program proposals are also strongly encouraged. Award durations are generally up to three years, with budgets typically ranging from $250,000 to $650,000. The program also considers proposals for conferences, workshops, rapid response research, and exploratory grants. Interested applicants are advised to discuss their proposals with the program director prior to submission.