**4. Conclusion**

In this chapter, we proposed the microcavity-array pattern substrate for electrical stimulation of stem cell EBs fabricated by micro and soft lithography technique, aiming at precise control of cell differentiation processes. We could obtain intracellular calcium signals responded to electrical stimulation in EBs simultaneously, indicating that the electrode device would be a promising experimental tool to regulate the cell differentiation processes. We believed that we represented a step on the way to precisely control of cell differentiation processes. Optimization of experimental parameters and improvement of the electrode device structures are current questions.
