Soft Plasmene Helical Nanostructures

Abstract

It is a new class of advanced materials combining tailorable organic ligands and inorganic building blocks that can be finely tuned with arbitrary size and shapes, [4] demonstrating unique structure-dependent properties such as gapdepended plasmonics, [1] n-doping or p-doping like properties, [5] transmutable optical and structural properties, [6] asymmetrical ion transport properties, [7] and inter/intra-plasmonic coupling. [8] While a focused ion beam (FIB) is able to program milling sites and milling depths precisely to obtain several 3D plasmene origami structures, [1,9] helical plasmonic structures have not yet been achieved.On the other hand, helical structures from plasmonic nanomaterials have recently attracted intense research due to their unique chiral optical properties. [10][11][12][13][14][15][16] For instance, a gold helix square lattice can block the circular polarization with the same handedness as the helices while transmit the other. [11] Hybrid nanoscrolls from MoS 2 or WS 2 and plasmonic Ag nanoparticles exhibited up to 500 times Plasmene is recently defined as 2D arrays of plasmonic nanoparticles, which could be fabricated by the bottom-up self-assembly approach and demonstrated a wide range of applications in sensing, energy harvesting, nanophotonics and encryption. Herein, this work further demonstrates a 3D helical plasmonic nanostructures that can be fabricated from 2D plasmene nanosheet. Inspired by chocolate curls-making process, a micro-spatulabased strategy is developed to selectively scrape substrate-supported plasmene to free space, which spontaneously folds the plasmene nanosheet into various complex helical nanostructures with controlled dimensions. 3D nanospirals can also be obtained by focus ion beam (FIB)-based lithography on free-standing plasmene. Helical plasmene structures are robust, exhibiting elastic mechanical properties and chiral optical response. This methodology represents a versatile fabrication route combining both bottom-up and topdown approaches to create soft plasmonic helical structures for potential applications in next-generation flexible nanophotonic devices.

Materials-Driven Soft Wearable Bioelectronics for Connected Healthcare

“…Top-down and bottom-up fabrication methods can be combined to produce flexible nanostructures. In a recent report, flexible plasmonic nanostructures were produced via a combination of drying-mediated self-assembly and focused ion beam (FIB) lithography . First, a soft free-standing monolayered plasmonic nanocrystal array (termed as plasmene sheets) was fabricated via a two-step drying mediated self-assembly of polystyrene-capped nanocrystals (Figure a). , Various 3D origami and kirigami structures could be obtained by selective FIB lithography which could arbitrarily define milling location and milling depth.…”

“…First, a soft free-standing monolayered plasmonic nanocrystal array (termed as plasmene sheets) was fabricated via a two-step drying mediated self-assembly of polystyrene-capped nanocrystals (Figure a). , Various 3D origami and kirigami structures could be obtained by selective FIB lithography which could arbitrarily define milling location and milling depth. In particular, 3D helical spiral nanospirals could then be obtained by the FIB-based kirigami process or microspatula-based selective scraping process (Figure b–g) . Such produced helical plasmene structures were very robust, exhibiting elastic mechanical properties and chiral optical response, indicating potential applications in next-generation soft nanophotonic devices and sensors.…”

“…In particular, 3D helical spiral nanospirals could then be obtained by the FIB-based kirigami process or microspatula-based selective scraping process (Figure 12b−g). 373 Such produced helical plasmene structures were very robust, exhibiting elastic…”

Active Control and Sensing Application of Ultra-Narrowband Circular Dichroism in Multilayer Chiral Nanorod Arrays

“…16−18 For instance, three-dimensional helical plasmonic nanostructures, prepared using micro-scratching technology, exhibit a significant chiral response for LCP and RCP within the 1.5−8.5 μm spectral range. 16 Furthermore, nonchiral nanostructures can also exhibit similar CD effects.…”

“…The double-layer chiral nanostructures, which can generate interlayer coupling, have been shown to enhance CD further. − For example, the vanadium dioxide-based double-layer gold arc chiral nanostructure displays a maximum circular dichroic response value of 0.7 in the near-infrared waveband . Three-dimensional chiral nanostructures possess more degrees of electromagnetic wave control, where controlling the relative distance and shape between different chiral unit cells can produce more extensive chiral optical properties. − For instance, three-dimensional helical plasmonic nanostructures, prepared using micro-scratching technology, exhibit a significant chiral response for LCP and RCP within the 1.5–8.5 μm spectral range . Furthermore, nonchiral nanostructures can also exhibit similar CD effects.…”