Thermally Driven Bimorph Nano Actuators Fabricated using Focused Ion Beam Chemical Vapor Deposition

Bimorph nano actuator fabricated with focused ion beam chemical vapor deposition (FIB- CVD) on MEMS heater is presented. The nano bimorph structure is composed of C₁₄H₁₀ and W(CO)₆ and the transferred thermal energy generated from the MEMS heater increases bimorph temperature. Due to the thermal strain mismatch of the two materials, carbon and tungsten, the nano bimorph bends toward C indicating larger CTE of tungsten containing material. The measured stroke is 600 nm projected from top and bimorph actuation is repeated for over 100 times without any indication of degradation of failure under controlled input voltage. Relation between measured stroke, difference in coefficient of thermal expansion (CTE) and temperature rise is derived using Denavit-Hartenberg notation and bimorph structure analysis. DeltaCTE is calculated to be 1.87 X 10-⁶K-¹, which is necessary value to design the presented type nano bimorph actuators with different geometry/dimension and to predict their operational conditions and expected performance.