Plasmon-driven nanowire actuators for on-chip manipulation

Abstract

Chemically synthesized metal nanowires are promising building blocks for next-generation photonic integrated circuits, but technological implementation in monolithic integration will be severely hampered by the lack of controllable and precise manipulation approaches, due to the strong adhesion of nanowires to substrates in non-liquid environments. Here, we demonstrate this obstacle can be removed by our proposed earthworm-like peristaltic crawling motion mechanism, based on the synergistic expansion, friction, and contraction in plasmon-driven metal nanowires in non-liquid environments. The evanescently excited surface plasmon greatly enhances the heating effect in metal nanowires, thereby generating surface acoustic waves to drive the nanowires crawling along silica microfibres. Advantages include sub-nanometer positioning accuracy, low actuation power, and self-parallel parking. We further demonstrate on-chip manipulations including transporting, positioning, orientation, and sorting, with on-situ operation, high selectivity, and great versatility. Our work paves the way to realize full co-integration of various functionalized photonic components on single chips.

Micro-scale opto-thermo-mechanical actuation in the dry adhesive regime

“…2b with the recorded temporal sequential optical images for a hexagonal plate. This observation generalizes the previously observed single motion freedom, either rotation 23 or translation 22 , 24 . Specifically, the hexagonal plate translates towards the upper axial direction of the micro-fiber with a speed of 3.4 µm/s, and, at the meantime, it rotates anti-clockwise (as viewed from the top side of the optical images) with a speed of 46 rpm (characterized in the leftmost panel of Fig.…”

“…Here, the asymmetry in the contact surface is identified to be the key enabling the translation, which is consistent with our observation that the translation direction is independent of light direction. This novel translation mechanism marks the essential difference between our scheme and another in a recent publication 24 —that proposes the asymmetry in the spatial distribution of optical absorption as the key factor and observes the dependence of the translation direction on light direction (see Sec. 6-B2 in the Supplementary Material for more discussions).…”

“…for lab-on-a-chip technologies 27 . Besides, the findings in these studies have demonstrated motions of specific-shaped gold plates either along the azimuthal 23 or axial directions 22 , 24 of the micro-fibers, but not both.…”

“…In this regard, a few recent studies have pointed out a new direction: the excitations of elastic waves in micro-objects could facilitate their locomotion on dry surfaces 22 – 24 , as an extension of macroscopic surface elastic-wave motors 25 , 26 . In these pioneering studies, elastic waves are excited by temperature changes in micro-objects through optical absorption based on fiber-based systems.…”

Epidermis‐Inspired Wearable Piezoresistive Pressure Sensors Using Reduced Graphene Oxide Self‐Wrapped Copper Nanowire Networks

“…The successive progress of nanomaterials synthesis and related device fabrication has ushered in many achievements in actuator/robotic devices, [ 24–27 ] energy storage devices, [ 28–30 ] biosensor devices, [ 31–34 ] flexible displays, [ 35,36 ] and human‐machine interfaces. [ 37,38 ] Several notable nanomaterials such as graphene, [ 39,40 ] metal nanoparticles (particularly liquid metal), [ 41–43 ] conductive polymers, [ 44,45 ] and metal nanowires/nanofibers [46,47] have been extensively exploited for developing next‐generation wearable electronic devices.…”