1. sample laser cantilever quadrant photodetector tip AFM measures x, y, and z dimensions. The AFM works by scanning a silicon or silicon nitride tip, with a radius on the order of nanometers, positioned at the end of a cantilever over a surface. As the tip is attracted (van der Waals forces) to the surface, the cantilever deflects. This deflection is then monitored by a laser. CONTACT MODE IMAGING To obtain a deflection image (for morphological contrast), the deflection of the cantilever is measured while the tip scans at a constant height. To obtain a height image, the sample height variations are measured while the tip scans at a constant deflection (force). Multimode AFM Dimension AFM AFM - Theory and Instrumentation cantilevers have spring constants which affect the downward force on the sample

2. TIP Specifics http://www.nanoscience.com/products/AFM_tips.html

3. nucleus membrane cell division AFM Imaging of Freeze-Dried NIH-3T3 Fibroblasts height image deflection image