Evaluation of nanoknife's edge angle for single cell cutting by using nanorobotic manipulators inside ESEM

Cell cutting is an important step in cell analysis processes. To address the single cell cutting at nano scale, Three types of nanoknives are designed in this paper. The first type of nanoknive was fabricated from a tungsten and the second type was fabricated from an atomic force microscopy(AFM)cantilever. In order to protect the nanoknife tip during the cell cutting, a novel nanoknife with a buffering beam is proposed. This kind of nanoknife was fabricated from a commercial AFM cantilever by focused ion beam (FIB) etching technique. The buffering beam can be also used to measure the cutting force based on its deformation. The spring constant of the beam was calibrated based on a referenced cantilever by using a nanomanipulation approach. The tip of the nanoknife was designed with a small edge angle 5 to reduce the compression to the cell during the cutting procedure. For comparison, two other nanoknives with different edge angles, i.e. 25° and 45°, were also prepared. An in-situ single cell cutting experiment was performed using these three nanoknives inside an environmental scanning electron microscope (ESEM). The cutting force and the sample slice angle for each nanoknife were evaluated. It showed the compression to the cell can be reduced when using the nanoknife with a small edge angle 5°. Consequently, the nanoknife was capable for in- situ single cell cutting tasks.