Soft robots, known for their adaptability, flexibility, and safety, have diverse applications in unstructured environments. However, current actuation methods for soft robots suffer from low energy efficiency and limited control bandwidth. To address this, this paper introduces a modularly designed miniature fluidic power source (mFPS) tailored for powering soft robotic actuators, providing capabilities similar to traditional servomotors for closed-loop feedback control. The detailed design methodology for sizing the mFPS is presented. A first-generation prototype is manufactured to assess its performance characteristics, including system efficiency and bandwidth. Additionally, the control capabilities of the mFPS is demonstrated by accurately controlling a fluidic artificial muscle’s position using a simple PID controller, achieving a rapid 16 mm step response in approximately 250 ms with a steady-state accuracy of around 0.2 mm. These results highlight the feasibility of our proposed soft robot actuation method, which holds promise for improving the dynamic response performance and control accuracy of various soft robots.