A method of multi-touch portable electronic device simulation using a non-touchscreen computer input device. Each of the TFTs comprises a gate, a source, a drain and a channel layer coupling the source to the drain. The first part comprises at least the power supply, radio part, antenna of the radio part, and means for communicating on the first link communication with the second part. A plurality of microwell matrices are held simultaneously by the frame structure and are hermetically closed by a corresponding number of allocated plugs, which are fastened to a base plate and a cover plate, respectively. The router, located on the Z-arm, moves downward to engage a router bit to the panel to depanel the printed circuit board from the panel. The present invention also discloses the atrial and ventricular cardiomyocytes formed from the stem cells, and the uses of the cardiomyocytes for repairing cardiac injuries and screening for new medicaments for treating cardiac injuries.