Towards a Microfluidic Microcontroller Circuit Library for Soft Robots

Abstract

Soft robotics has seen an exponential growth in the past decade, in part because the transition to soft materials has made a wider range of applications possible. Tasks involving contact with fragile objects or unstructured environments are particularly amenable to devices based on soft materials. To date, research has primarily focused on the development of soft analogs to traditional sensors and actuators while controllers for soft robots have tended to rely on common rigid electronic components. We aspire to create a library of elastomer-based devices that can evolve soft controllers beyond component-level demonstrations and towards system-level completeness taking inspiration from electronic microcontrollers. Our approach combines microfluidic circuit designs with soft robotic fabrication techniques to create fluidic microcontroller components that are composed of soft materials and are of minimal size. We have identified the shift register, oscillator, and demultiplexer as key circuit elements for both individual functionality and for multi-component systems that can mimic microcontroller behaviors. In this paper, we present a review of fluidic circuits, fabrication processes, and implementation of these circuits into soft robotic platforms. In this work, we demonstrate a shift register, demultiplexer, and oscillator. They contain characteristics such as memory storage, data communication, and timing capabilities.