High temperature piezoelectric crystal (HTPC) sensors are desired for future propulsion component structure health monitoring, operating parameters optimization, turbine engine control and health monitoring, as well as improving performance and maintainability of power production facilities and other rotary combustion engines. Recently discovered high temperature piezoelectrics showed stable piezoelectric properties and high resistivity at temperatures close to its melting point (~ 1500 C) , which is very promising for high temperature sensor applications. The Phase I results demonstrated excellent temperature sensing and vibration sensing performance at temperature up to 1000 C (> 1800 F). In Phase II, low profile HTPC microsensors design, fabrication and attachment will be further investigated and optimized. Highly sensitive HTPC piezoelectric structural microsensors will be prototyped and characterized for temperature, stress and acceleration measurements at temperatures up to 2000 oF. HTPC microsensor reliability will also be studied in Phase II. HTPC microsensors will significantly advance NASA, DOD and industrial high temperature measurements because of their low profile, simple structure, high sensitivity, quick response, and high reliability.