Monolithically fabricated double-ended tuning-fork-based force sensor

A highly sensitive force sensor that is suitable for precise gap control is presented. It combines a double-ended tuning fork (DETF) resonator with a cantilever beam. When the force to be measured is applied to the cantilever beam, the resonant frequency of the DETF beam changes due to the change in axial force. The DETF-based sensor can detect the force as an amplitude change due to the resonant frequency change. The performance of the sensor was theoretically and experimentally investigated. The sensor is rigid and can measure the force with a change in the sample or probe height of less than about 1nm. The experimentally attained minimum detection limit of the force was 19μN and this can be improved by more than one order of magnitude according to theoretical estimation. The combination of the DETF-based sensor and the fixed probe or sample is expected to provide the measurement of the surface force with precise gap control. It can be useful for various fields such as interface science, probe microscop...