DARPA’s Defense Sciences Office is seeking submissions of innovative basic or applied research concepts in the technical domain of developing novel metrology for understanding wave propagation in compressible fluids. The Liquid Surge program seeks foundational understanding by developing novel prototype metrology to study coupled thermodynamic, mechanical, and compositional responses to transient wave phenomena in complex liquid media. New methods should be able to examine relationships between molecular-scale processes and macroscopic fluid behavior across controlled operating conditions. These new prototype methods of measurement should be presented in a form that makes typically unwieldly experiments more accurate, representative, and controllable than traditional full-scale testing methods. Liquid Surge is a two-phase program: Phase – Feasibility Study– base – 9 months – up to USD$550,000 Phase 2 – Proof of Concept – option – up to USD$445,000 Abstract proposals are due 3 November 2026. This call is issued under the Disruptioneering Program Announcement DARPA-PA-25-07.