Next Dimension Technologies and Caltech will jointly develop a handheld detector to meet the Armys need for a field-based illicit drug identification system. The project will focus on the design and development of a dual-mode chemiresistive sensor array capable of detecting key drugs of interest, including synthetic cannabinoids and opioids. Novel sensing materials, with enhanced chemical sensitivity towards the drug targets will be developed and integrated into the sensor array. The approach will involve advanced sampling methods that allow for versatile and simultaneous detection from both vapor and liquid phases, and the platform will be designed to allow for additional drug targets to be added in future prototypes. Key performance metrics including sensitivity, specificity and sensor stability will be evaluated. At the conclusion of the project, a prototype concept that meets the Armys requirements for accuracy, cost, portability, ease of use, ruggedness, longevity, and power consumption, will be developed.