Geometrically Structured Nanomaterials for Nanosensors, NEMS, and Nanosieves

Abstract

Recently, geometrically structured nanomaterials have received great attention due to their unique physical and chemical properties, which originate from the geometric variation in such materials. Indeed, the use of various geometrically structured nanomaterials has been actively reported in enhanced‐performance devices in a wide range of applications. Recent significant progress in the development of geometrically structured nanomaterials and associated devices is summarized. First, a brief introduction of advanced nanofabrication methods that enable the fabrication of various geometrically structured nanomaterials is given, and then the performance enhancements achieved in devices utilizing these nanomaterials, namely, i) physical and gas nanosensors, ii) nanoelectromechanical devices, and iii) nanosieves are described. For the device applications, a systematic summary of their structures, working mechanisms, fabrication methods, and output performance is provided. Particular focus is given to how device performance can be enhanced through the geometric structures of the nanomaterials. Finally, perspectives on the development of novel nanomaterial structures and associated devices are presented.

Laser-induced, Surface Plasmon-enhanced Two-photon Excitation for Efficient Chemical Functionalization of Nanostructured Gold Surfaces

“…Water (5 mL) was subsequently added and the mixture was extracted with dichloromethane (3 × 10 mL), dried over anhydrous Na 2 SO 4 , concentrated in vacuo, and purified by flash column chromatography over silica gel (60Å, 0.040-0.063 mm (SDS) using a mobile phase consisting of a mixture of dichloromethane-methanol (gradient from 2% v/v methanol/dichloromethane to 10% v/v methanol/dichloromethane) to afford pure compound 2 (93 mg, 94%). 1…”

“…The solvent was removed in vacuo and the resulting residue purified by flash column chromatography over silica gel (60Å, 0.040-0.063 mm (SDS) using a mobile phase consisting of a mixture of hexane-ethyl acetate (gradient from 30% v/v ethyl acetate/hexane to 100% v/v acetate/hexane) to give NV-SNaph as a yellow solid (26 mg, 50%). 1…”

“…Developments in the fields of nanoscience and nanotechnology have resulted in the emergence of a wide range of different nanostructures with unique chemical and physical properties. [1][2][3][4][5][6][7][8][9][10][11][12] Of particular interest in this context is the interaction between nanomaterials and light. Light offers a large number of advantages when applied to nanomaterials: it is straightforward to apply and can be remotely controlled both spatially and temporally; it is relatively harmless to living organisms at longer wavelengths; and it is easily implemented on various platforms, providing an efficient means to exert external stimuli.…”

Optically Activated 3D Thin‐Shell TiO2 for Super‐Sensitive Chemoresistive Responses: Toward Visible Light Activation

“…Compared to other competing techniques such as self‐assembly, electrospinning, and many other bottom‐up methods, one of the notable technical advantages of this microelectromechanical system‐integrated method is the direct patterning of 3D scaffolds on the electrodes. [ 21–23 ] Therefore, the further TiO 2 deposition using ALD can be done without any additional transferring steps, which generally lead to poor contact issues between the electrodes and the deposited functional materials. [ 24,25 ] To apply 3D TiO 2 to gas sensors, we fabricated 3D TiO 2 on a SiO 2 /Si substrate with Pt interdigitated electrodes (IDEs).…”

Perfectly Aligned, Air‐Suspended Nanowire Array Heater and Its Application in an Always‐On Gas Sensor

“…Recent advances in nanofabrication technologies have made it possible to study the geometric effect of nanomaterials, which can further improve device performance. [ 17 ] The proposed geometry allows us to explore the optimized design of heaters, which leads out the potential thermal capability of the nanowires. In particular, we focused on their ability to confine heat in a localized region, thereby suppressing beam conduction loss to the substrate.…”