Emergence of traveling waves in linear arrays of electromechanical oscillators

Abstract

Traveling waves of mechanical actuation provide a versatile strategy for locomotion and transport in both natural and engineered systems across many scales. These rhythmic motor patterns are often orchestrated by systems of coupled oscillators such as beating cilia or firing neurons. Here, we show that similar motions can be realized within linear arrays of conductive particles that oscillate between biased electrodes through cycles of contact charging and electrostatic actuation. The repulsive interactions among the particles along with spatial gradients in their natural frequencies lead to phase-locked states characterized by gradients in the oscillation phase. The frequency and wavelength of these traveling waves can be specified independently by varying the applied voltage and the electrode separation. We demonstrate how traveling wave synchronization can enable the directed transport of material cargo. Our results suggest that simple energy inputs can coordinate complex motions with opportunities for soft robotics and colloidal machines.

Photomorphogenesis of Diverse Autonomous Traveling Waves in a Monolithic Soft Artificial Muscle

“…Creating an adaptive, autonomous soft robotic system that enables programmable shape morphing would be of interest for both scientific and engineering applications. , Living organisms, such as gastropods, cephalopods, batoids, and so forth, can morph their soft, sheet-like tissues into 3D wavy morphologies and self-oscillate to generate traveling waves (TWs) that offer a versatile approach for achieving propulsion, transportation, and locomotion in natural systems. − However, to artificially generate TWs, conventional robotic systems need numerous discrete actuators, each of them individually controlled and powered in a coordinated fashion, which inevitably leads to complexity in design, fabrication, control, and powering of the systems which especially turns impossible when the length scale of a robotic system is miniaturized to millimeters or even smaller. The use of soft active materials (SAMs) that possess intelligent morphing behaviors inherent to the materials themselves and allow self-oscillating motion driven by a constant static energy input can endow manmade robotic systems with autonomous intelligence, which would effectively reduce the complexity of the systems .…”

Mutual synchronization of rotary pulses in coupled tunnel‐diode oscillator lattice loops

“…1 On the other hand, scalable mechanical actuation can be realized by traveling waves that are spontaneously developed in linearly connected electromechanical oscillators. 2 Their properties have been investigated in a variety of oscillator networks, including a chain of selfsustained oscillators described by the Ginzburg-Landau equation, 3,4 unidirectionally coupled parametric oscillators, 5 bistable self-sustained oscillators with inductive coupling, 6 bistable Duffing oscillators with unidirectional coupling, 7,8 nonlinearly coupled oscillators, 9,10 and excitable oscillators such as the FitzHugh-Nagumo oscillators. [11][12][13][14][15] In addition, pulsed wave tends to rotate in an oscillator lattice loop.…”

Sparsity-driven synchronization in oscillators networks

“…it is the sole network attractor 10,11,21 . Conversely, in sparse networks, the ISS is often sharing the system state-space with other synchronization patterns such as q-twisted states 10,22,23 , traveling waves [23][24][25] , solitary and chimera states [26][27][28][29] . In such a scenario, the ISS possess a domain of attraction, i.e., a finite portion of the network state-space from where all trajectories converge to the ISS.…”