| 摘要 |
The atomic force sensor head comprises a cantilever beam (50) forming an integral part of a body (53) from which it extends such that it has a free end to carry a member (55) for interaction with a surface to be investigated. As said member (55) is brought close to said surface, atomic forces will cause a deflection of said cantilever (50). This deflection is translated into a variation of an electrical value, such as a capacitance. A capacitor (57) is formed by a pair of electrodes (51, 52) coated onto the cantilever beam (50) and said body (53), respectively. The deflection of said cantilever beam (50) causes a variation of the distance (s) between said electrodes (51, 52) and, hence, of the capacitance. An improvement of the sensitivity and stability of this arrangement is made possible by filling the gap between the said electrodes (51, 52) with materials (54, 56) having different dielectric constants and different thicknesses. With a relation of 1:10 of the dielectric constants and a thickness relation of 1:5, an improvement factor of about 40 can be obtained. |
