Scalable Fluidic Matrix Circuits for Controlling Large Arrays of Individually Addressable Actuators

A fundamental challenge of pneumatically powered soft robotic devices is the scalability of fluidic control systems to address each actuated degree of freedom, as the required electromechanical valves are bulky and expensive. Previous solutions have compromised the reprogrammability and/or the bandwidth of the fluidic system. This article describes and models a fluidic subsystem, a fluidic matrix circuit (FMC), that enables the independent control of many (N2$N<^>{2}$) actuators using a limited number (2N$2 N$) of electromechanical valves. The fundamental unit, a fluidic logic module (FLM), generates a bidirectional pressure signal (vacuum or positive pressure) based on the state of the mass flow through it. Thus and array of pneumatic actuators can be addressed individually using an array of FLMs integrated into a matrix (i.e., an FMC), with electromechanical valves to switch the mass flow through each row and column of the matrix. The resulting refresh rates are an order of magnitude faster than previous approaches. This concept with a prototype FMC able to control 25 actuators using 10 electromechanical valves for applications including a fluidic shape display and a wearable haptic vest is demonstrated. This approach could enable more complex and sophisticated soft robotic devices with scalable control hardware.