4-DOF Wireless Underwater Combustion-Driven Soft Robot

MUDKIP is a soft underwater robot engineered with hydrogen-oxygen electrolysis-driven buoyancy control and impulse combustion propulsion, achieving 4 degrees of freedom in a single integrated system. Three modular Buoyancy Control Devices (BCDs) independently regulate depth and orientation by inflating balloons with electrolytically-produced H₂ and O₂ gas, enabling two-axis pitch and roll control. A stainless-steel combustion chamber ignites the stored gas mixture via a kilovolt spark plug, generating 21 N of thrust for forward propulsion along the x-axis. The waterproofed PLA hull — sealed with XTC-3D epoxy, Flex Seal, JB Weld, and double O-ring compression joints — survived over 5 hours of full submersion with zero leakage. All systems are wirelessly controlled via 2.4 GHz WiFi, with an onboard Arduino managing electrolyzer switching, power bank sequencing, and ignition through a custom MOSFET-driven circuit architecture.