Embodying mechano-fluidic memory in soft machines to program behaviors upon interactions

TL;DR

This paper demonstrates how soft machines can be designed with embedded mechanical memory using elastic bistable shells and fluidic circuits, enabling autonomous behavior changes without centralized computation.

Contribution

It introduces a novel approach to embedding memory in soft robots through elastic bistability and fluidic circuits, allowing programmable and autonomous responses.

Findings

Soft machines can switch behaviors based on embedded mechanical memory.

Fluidic circuits enable both long-term and short-term memory in soft robots.

The approach allows autonomous behavior changes without centralized control.

Abstract

Soft machines display shape adaptation to external circumstances due to their intrinsic compliance. To achieve increasingly more responsive behaviors upon interactions without relying on centralized computation, embodying memory directly in the machines' structure is crucial. Here, we harness the bistability of elastic shells to alter the fluidic properties of an enclosed cavity, thereby switching between stable frequency states of a locomoting self-oscillating machine. To program these memory states upon interactions, we develop fluidic circuits surrounding the bistable shell, with soft tubes that kink and unkink when externally touched. We implement circuits for both long-term and short-term memory in a soft machine that switches behaviors in response to a human user and that autonomously changes direction after detecting a wall. By harnessing only geometry and elasticity, embodying memory allows physical structures without a central brain to exhibit autonomous feats that are typically reserved for computer-based robotic systems.