Large Indentation Method to Measure Elasticity of Cell in Robot-Integrated Microfluidic Chip

Robot-integrated microfluidic chip is a promising tool to realize mechanical characterization of a single cell with high throughput and high accuracy. The microfluidic chip used in our system has a pair of mechanical microprobes to measure deformation and reaction force of cells. In our previous studies, we measured the elasticity of cells in this measurement system. However, there were some problems on the measurement method limited in small deformation regions of cell. To avoid these problems, we changed the measurement method to utilize large deformation regions of cell. First, we proposed a differential-type sampling moiré method to extend the range of the force or displacement measurement. Second, the mechanical model of the cell was improved to express the deformation characteristics up to large deformation region. The deformation model was derived from high-molecular theory. Therefore, the measured elasticity was related to the intracellular filament network. As a result, we accomplished in measuring the elasticity of the cells using the experimental data in a large deformation region. This study provided us with a more practical and reliable method to measure cellular elasticity.