Microfabricated Force Sensors and Their Applications in the Study of Cell Mechanical Response

Living cells are sensitive to their mechanical environments and they transduce mechanical stimuli into biological responses. Developing suitable experimental techniques is essential to explore the question on how cells respond to mechanical stimuli. The current major techniques normally induce small cell deformations and measure their corresponding cell force response (small) in the range of 1 pN to 10nN. However, in many physiological conditions, cell deformations can be large (comparable to the cell sizes) inducing large force response. In order to explore cell mechanical behavior under large deformations, we introduce a class of microfabricated force sensors. The sensors, consisting of a probe and flexible beams, normally measure cell force response in the range of 1nN to 1 mu N. Both the one- and two-component force sensors have been developed, and have been used in cell experiments. These experiments showed the versatility of the force sensors. Representative experimental results on cell stretch force response, cell indentation force response, and in situ observation of the actin cytoskeleton during indentation, will be given. These results provide significant insight on cell mechanical response under large deformations.