BiFlu2: A Miniaturized Electro-Fluidic Circuit for All-On-Board Control of Hydraulically-Actuated Biorobotic Organs

This paper presents the design and implementation of BiFlu2, a compact electro-fluidic circuit engineered for implantable biorobotic organs with hydraulic actuators. BiFlu2 enables fluidic control with a limited number of components, i.e. two bistable 3-way valves for bidirectional fluid transfer and an additional one for fluid (de)multiplexing. The system is designed to operate with minimal power consumption, making it suitable for long-term operation upon implantation. The design incorporates an ESP32 microprocessor for wireless remote control, as well as pressure sensors to monitor real-time actuators' performance. BiFlu2 has been tested and validated through simulations and experimental setups, demonstrating efficient hydraulic control of an artificial detrusor integrated with a soft artificial bladder. The experimental results show reliable performance, low power consumption, and effective actuator control for the voiding process of an artificial bladder provided with a hydraulic detrusor. This study highlights the BiFlu2 potential for use in fluidically actuated implantable biorobotic organs, where compact size and energy efficiency are critical. Refer to the supplementary video for a summary of our findings.