Hybrid Membrane�Solenoid Valves for High-Flow, Precisely Controlled Soft Robotic Actuation
Nikola Velimirovic, C. David Remy, Daniel Bruder
AI summary
Problem
Scaling fluid-driven soft robots to hyper-actuated systems is hindered by the piping problem, where numerous valves increase mass, volume, and cost. Existing compact solenoid valves lack flow capacity, while large membrane valves lack precise electronic control.
Approach
The authors designed a modular hybrid valve that integrates a miniature solenoid pilot directly into a high-flow membrane valve body. The solenoid switches a small control chamber to open the membrane, combining high mass flow with precise electronic regulation in a single 3D-printable module.
Key results
- Faster pressurization and venting rates compared to standard solenoid valves
- Higher control bandwidth across tank pressure regulation tests
- Over five-fold increase in mechanical power output during weight curling
- Successful integration into a planar two-stage soft robot demonstrating compact scalability
Why it matters
Provides a scalable, compact, and cost-effective fluidic control solution for hyper-actuated soft robots, preserving manufacturing advantages while enabling complex dynamic behaviors.
Abstract
Fluid-driven soft robots promise high-dimensional motion and cost-effective scalability, but their performance is constrained by the limited flow capacity of compact solenoid valves and the integration challenges of large membrane valves. This paper introduces a modular hybrid valve architecture that couples a high-flow membrane valve with an integrated miniature solenoid pilot. The resulting composite element achieves both high mass flow rates and precise electronic control while maintaining a compact, lightweight, and fabrication- friendly design. We present the design, modeling, and control strategies for these valves, and evaluate their performance through three experiments: tank pressure regulation, actuation of a weight-curling robot, and integration into a planar two- stage tossing robot. Across all cases, the hybrid membrane valves significantly outperformed solenoid valves, exhibiting faster pressurization and venting, higher bandwidth, and over a five-fold increase in mechanical power output. These results demonstrate that membrane–solenoid hybrid valves provide a scalable and integrable solution for overcoming the “piping problem,” enabling hyper-actuated soft robotic systems.