In-situ Single Cell Mechanics Characterization of W303 Yeast Cells using Nanoneedles inside Environmental-SEM

In this paper, the characterizations of cellular mechanics of W303 yeast cells have been conducted using nanoneedles inside environmental-SEM (ESEM). This enhanced ESEM system comprises of a standard ESEM instrument as a nano imaging tool, a cooling stage as a cellular biology´s humidity controller and 7 D.O.F. linear actuators as nanomanipulator/effector. Four types of nanoneedles have been used in the experiments, i.e. silicon (Si) nanoneedle, titanium (Ti) coated Si nanoneedle and tungsten (W) nanoneedles. The former two nanoneedles are fabricated using 2 N/m spring constant´s cantilevers. While the latter nanoneedles are fabricated using 0.09 N/m and 2 N/m spring constant´s cantilevers (W_0.09 and W₂ nanoneedles). All types of the nanoneedles, i.e. Si, Ti-Si, W_0.09 and W₂ nanoneedles are able to be used for single cells´ local stiffness characterizations. This ability can be used in future fast disease detection where the disease cells may shows different cell mechanics properties compare to the normal cell. In addition to this, the Si-Ti and W₂ nanoneedles have shown an ability to penetrate the cell without cell bursting. This ability is important in the future single cell surgery where the cell damage can be eliminated as much as possible.