SMALL AFM CANTILEVERS FOR BIOLOGICAL APPLICATION

Atomic Force Microscope is of special interest to biologists since it enables real time imaging and force measurements on biological tissue. To observe the biological process of interest in a reasonable time with high force sensitivity, high resonance frequency cantilevers with low spring constant are required while maintaining a high signal to noise ratio. These requirements can be met by reducing the dimensions and mass of the cantilever. Silicon nitride (SiN) is used to fabricate the AFM cantilevers; the body of the probe is exists of a double layer of the negative photopolymer SU-8. This provides a simple and cheap way of attaching a body to the cantilevers. Figure 1 shows an overview of a probe with 6 cantilevers. Figure 2 shows a close-up of a lever with dimensions 35 µm x 6 µm. A metal pad is present at the extremity of the cantilever, serving as reflecting layer for beam deflection sensing.