Characterization of electroformed nickel microstructures

Electroformed nickel resonators were constructed and tested in the temperature range of - 40 to 110 degrees C. The temperature sensitivities of the resonant frequencies are - 150 ppm/degrees C, - 200 ppm/degrees C, and - 3000 ppm/degrees C for cantilever beams, ring structures, and clamped-clamped bridges, respectively. The built-in stress for the bridge was estimated to be approximately 2 X 109 dyne/cm2. No resonant frequency shift was detected after long-term (over 60 days), large amplitude vibration. This implies that the electroformed nickel is a viable material for the construction of resonant mechanical sensors.