This thesis presents the development, implementation, and validation of an untethered microcombustion system utilizing liquid hydrogen peroxide and butane as fuels. The research focuses on augmenting the autonomy and power density of small robotic platforms through the creation of a compact, high-energy microcombustion system designed for onboard integration. The thesis details the optimization of a spark timing system using analog circuits to reduce power consumption and weight, alongside the development of a pump control system employing a motor driver and PCB boost converter for smooth hydraulic movements in underwater robotics, like tail beating in fish-like robots. Additionally, it discusses potential future enhancements, including wireless technology integration, underscoring the project's contributions to advancing mobile robotic systems.