A force generator system that provides force information to a practitioner performing remotely controlled robotic surgery based on magnetorheological fluid (MRF) was developed. The actuator provides the operator a wide range of force corresponding to various tissue properties. The actuator enhances the percutaneous feeling of a surgeon interacting remotely with tissues in robotic bone biopsy. The force profile of bone drilling was characterized and modeled. The range of the force and operational bandwidth required for drilling operations was determined. The model characterizes the axial forces recorded while drilling perpendicular to the long axis of femurs in different animal specimens. The findings were used to design an actuator suitable for surgical applications, principally bone biopsies. To develop the actuator prototype, a magnetic circuit was designed and an appropriate MRF was selected. The magnetic circuit was validated by magnetostatic analysis. The final design of the actuator prototype was developed based on experimental observations. The actuator produces an output force appropriate for bone biopsy (high range of forces). The hysteretic behavior of the proposed actuator was modeled by characterizing the relationship between the input and output measurements. To construct a model of the actuator, a master-slave robotic biopsy system was setup and used to obtain input and output measurements for various animal tissues. These measurements were then used as estimators and validators of a nonlinear Hammerstein-Wiener (H-W) model. The nonlinear model was verified by comparing the measured data with the simulation results under various test conditions. The H-W model can predict the behavior of the MRF actuator with high precision. The H-W model was used to eliminate hysteresis in a closed-loop control system. Experiments were performed to demonstrate the efficacy and advantages of the H-W modeling and control technique. The H-W control tracked the input signal, recorded from various tissues via a slave robot, while compensating for magnetic hysteresis, to achieve optimal performance. In conclusion, the MRF-based actuator designed in this study, with its control system, can be used in surgical robotic operations that involve a high range of force measurements.