Polymer MEMS for measuring single cell forces

We have developed a polymer MEMS sensor for measuring mechanical forces generated by single adherent cells. Mechanical forces are known to play a role in cell regulation, and measuring these forces is an important step in understanding cellular mechanotransduction. The sensor consists of four polystyrene microcantilever beams with cell adhesion pads at each end. Finite element analysis was used to guide the design of a compound cantilever to allow measurement of forces in multiple directions. The device was evaluated by measuring forces generated by WS-1 human skin fibroblasts. A single cell was placed on the sensor using a custom micromanipulator. Forces were calculated by optically measuring the deflection of each probe during cell attachment and spreading. Measurements were performed on normal cells and those treated with cytochalasin D to disrupt the actin cytoskeleton. Cytochalasin D treated cells showed a significant decrease in force. This device can be used to evaluate the mechanical response of cells to a variety of chemical, mechanical, and other environmental stimuli.