A soft, high-frequency oscillator for autonomous movement of a soft robot

Autonomous movement is essential for enhancing the adaptability and functionality of fully soft robots. Soft oscillators made from flexible materials offer a promising alternative to rigid electronic components. However, they are often constrained by low operating frequencies or limited integration with soft robotic systems. Here, we present a soft, high-frequency oscillator that enables autonomous locomotion in a soft robot. This oscillator is based on feedback control from a soft NOT gate that integrates a customized piezoresistive composite—graphite frameworks (GFs) embedded in polydimethylsiloxane (PDMS)—with dielectric elastomer actuators (DEAs). The system enables rapid signal oscillation at frequencies up to ~78 Hz. The oscillator leverages a minimum-energy structure to transfer the oscillatory deformation into the crawling behavior of a soft robot. Additionally, the oscillation frequency can be tuned through three parameters: input voltage, charging resistance, and capacitance. This work demonstrates a scalable and tunable strategy for embedding high-speed autonomous control in soft robotic platforms.