A topology optimization method for design of compliant mechanical amplifiers for piezoceramic stack actuators is presented. Previously the optimization was done assuming that the stack actuator provided a constant unit load to the compliant mechanism. However, it is well known that the best actuator performance occurs when the stiffness of the stack is considered and matches the stiffness of the surrounding coupling structure. In this paper an improved formulation is presented where the piezoelectric properties and stiffness of the stack are included along with an external spring representing a resisting load the actuator is working against. The optimization problem formulation, finite element implementation, solution algorithm are discussed. Two design examples are presented which illustrate the effect of the stiffness of the external spring and the size of the design domain on the topology of the solution.