This thesis presents the design of four force sensors for cell injection application: (1) MFC (Macro Fiber Composite) cantilerver force sensor, (2) PVDF (polyvinylidene difluoride) and piezoresistive elmement based fixed-guided beam force sensor, (3) PVDF and MFC films based fixed-guided beam force sensor and (4) fixed-guided beam based active force sensor. Firstly, the most widely used micro-force sensing methods are reviewed and the most promising piezoelectric force sensors are chosen as the research target. Secondly, four piezoelectric force sensors of different working principle are successively designed, analyzed by FEA (finite element analysis), manufactured, calibrated and tested for crab embryo injection. The contribution mainly lies in two points. Firstly, the first exploration of MFC film acting as force sensor in cell injection application is presented, which shows that MFC film can detect mN-level force. Secondly, the developed force sensors can not only measure pure 1-D cell injection force, but also serve as cell holder devices, which improved the cell injection stability. Extensive experimental studies have been carried out to demonstrate the effectiveness of the developed micro-force sensors in cell injection applications.