Through Army SBIR funding, NanoSonic has created and empirically optimized viscoelastic HybridSil polyurethane siloxane seat cushions that provide improved pressure distribution and Multi-Axial Simulation Table (MAST) vibration dampening over currently employed Commercial- Off-The-Shelf (COTS) seat cushions. The foundation of this effort was the synthesis of novel polyurethane siloxane foams and the correlation of their copolymer composition and crosslinking density with vibrational damping, pressure distribution mapping, and mechanical properties. ASTM D 3574 mechanical testing indicates HybridSil seat cushions maintain dimensional stability after extended fatigue testing. H-point testing completed in accordance with FMVSS-202A indicates NanoSonic’s seat cushions afford comparable positional values to the current employed seat cushions and thus have direct integration potential.