A Vapor Phase Trinitrotoluene Threshold Detector Enabled by Nonlinear Feedback

The standoff detection of energetic materials is a critical challenge in national security and defense. The detection of solid energetic materials is particularly challenging, as these materials have extremely low vapor pressures at room temperature. Accordingly, the species have very low vapor phase concentrations. This letter presents a bifurcation-based resonant mass sensor architecture, a functionalization method, and sensor testing results demonstrating a low-cost, tunable sensitivity trinitrotoluene trace vapor detector. This detector leverages TIPS-Pentacene as a selective functional layer on a bulk-acoustic wave sensor and exhibits an estimated limit of detection below 480 ppb in N
₂
.