Phototunable Rayleigh 3D Soft Self-Oscillator Enabling Versatile Biomimetic Tubular Peristaltic Pumping

Abstract

Living tubular organs can spatiotemporally and cyclically deform their muscular walls to implement adaptable and sustainable peristaltic pumping applicable to broad matter, achieved via asymmetric and non-equilibrium self-oscillating deformations of muscular walls. However, man-made tubular soft actuators have been limited to pumping a few simple matters, because of their reciprocal and monotonic wall motions that cannot break time-reversal symmetry and system equilibrium to gain adaptable and sustainable pumping. Here, a phototunable Rayleigh 3D soft self-oscillator (PR3DSSO) capable of multimodal, nonreciprocal, self-sustainable wall deformations is presented. PR3DSSO's design leverages two direction-and-dimension-phototunable tubular instabilities: snapping and postbuckling. The post-buckling instability can generate local-wall origami which cannot only fold local walls into multimodal shape-mode waves, but also break wall-motion symmetry; snapping instabilities help break equilibrium in wall motions to initiate autonomous wall motions. These phototunable-instabilities-driven wall deformations unprecedentedly create Rayleigh-like 3D wall motions, which allow for versatile biomimetic tubular peristaltic pumping adapt to broad matter. Our PR3DSSO would spur creative life-like active-material designs and novel pumping functions.