Modeling and simulation of milling frozen biological samples by focused ion beam

Focused Ion Beam (FIB) has been used widely for sample preparation in material research and nanoscale device fabrication. The introduction of FIB system to biological samples preparation, especially for frozen samples, provides the potential to produce delicate submicron geometries on the samples, as well as the potential to be fully digitally controlled. In this paper, we first study the ion interactions with water and different cryoprotectants, and the sputtering yields under different conditions are estimated as the milling rate. A geometric simulation model is also proposed which can be used as a process planning tool to perform cryo-sectioning by FIB. Finally, discussions and suggestions for future work are presented.