A Soft Oscillator with On-The-Fly Tunable Dynamics for Adaptive Robotics

Abstract

Autonomous and mobile soft robots require internal oscillators, similar to a biological heart, to generate rhythmic motions. However, existing soft oscillators typically have fixed operational parameters and suffer from an inherent coupling between control input and power output, limiting their versatility and adaptability. This paper addresses this challenge by introducing a new design paradigm: a soft, multi-port, bistable oscillator whose core nonlinear energy landscape can be continuously and actively tuned on-the-fly. Our approach, based on mechanically reconfiguring the physical constraints of a bistable elastomeric structure, achieves a decoupling of kinematics (frequency) from dynamics (output pressure). We demonstrate this principle in two modes: first, active programming, where we continuously modulate the oscillator’s coupled frequency-amplitude relationship in real-time under a constant power input. Secondly, we demonstrate passive adaptation, where an autonomous walker powered by our oscillator exhibits physical intelligence. By physically interacting with a confined environment, the walker autonomously and instantaneously adapts its gait from a low-frequency, large-amplitude mode to a high-frequency, small-amplitude mode. This work provides a new pathway for creating adaptive, intelligent soft robots that can autonomously respond to their physical world without any electronic computation.