Authors: Y. Kim, M. Cha, H. Kim, S. Lee, J. Shin, J. Lee
Affilation: Seoul National University, Korea
Pages: 458 - 461
Keywords: NMT, ultra-thin gold membrane, hydraulic pressure
This work deals with ultra-thin metal-based nanomechenical transducers that have potentials for extraordinary sensitivity. This nano membrane transducer (NMT) consists of a flat thin film of gold with 30-60 nm thickness freely suspended over large square openings with the side dimensions of 50-500 m. This work deals with the fabrication process and the testing method to obtain pressure sensitivity. We measured capacitance changes caused by the deformation of gold membrane due to a small hydraulic pressure. A discrete amount of water in a series of droplets (50 l) was added or subtracted to control the hydraulic pressure. This amount is equivalent to the water head change of 1.7 mm. The deflection of the gold membrane and eventually the pressure sensitivity were calculated. The average value of capacitance per unit amount of droplet added or subtracted was ~5 fF. Thus the deflection at the center of membrane was 198 nm and the pressure sensitivity was 0.3 fF/Pa. Even though the pressure sensor is not our ultimate goal, this result is promising for the further development in this direction as well as the use for the chemo-mechanical sensing.