Highly sensitive sensor arrays are in high demand for prospective applications in remote sensing and imaging. Measuring microscopic deflections of compliant micromembranes and cantilevers is developing into one of the most versatile approaches for thermal, acoustic and chemical sensing. Here, we report on an innovative fabrication of compliant nanocomposite membranes with nanoscale thickness showing extraordinary sensitivity and dynamic range, which makes them candidates for a new generation of membrane-based sensor arrays. These nanomembranes with a thickness of 25-70 nm, which can be freely suspended over large (hundred micrometres) openings are fabricated with molecular precision by time-efficient, spin-assisted layer-by-layer assembly. They are designed as multilayered molecular composites made of a combination of polymeric monolayers and a metal nanoparticle intralayer. We demonstrate that these nanocomposite membranes possess unparalleled sensitivity and a unique autorecovering ability. The membrane nanostructure that is responsible for these outstanding properties combines multilayered polymer/nanoparticle organization, high polymer-chain orientation, and a pre-stretched state.

We report the focusing of surface plasmon polaritons by circular and elliptical structures milled into optically thick metallic films or plasmonic lenses. Both theoretical and experimental data for the electromagnetic nearfield is presented. The nearfield is mapped experimentally using nearfield scanning optical microscopy and plasmonic lithography. We find that the intensity at the focal points of the plasmonic lenses increases with size.

Far-field optical lens resolution is fundamentally limited by diffraction, which typically is about half of the wavelength. This is due to the evanescent waves carrying small scale information from an object that fades away in the far field. A recently proposed superlens theory offers a new approach by surface excitation at the negative index medium. We introduce a far-field optical superlens (FSL) that is capable of imaging beyond the diffraction limit. The FSL significantly enhances the evanescent waves of an object and converts them into propagating waves that are measured in the far field. We show that a FSL can image a subwavelength object consisting of two 50 nm wide lines separated by 70 nm working at 377 nm wavelength. The optical FSL promises new potential for nanoscale imaging and lithography.The discovery of Ernst Abbe in 1873 set the fundamental far-field resolution limit for an optical lens known as the "diffraction limit", which typically is about half a wavelength. 1,2 Although shorter wavelength electron beams and X-ray sources have improved resolving power, 3,4 the diffraction limit remains a formidable barrier. Near-field scanning optical microscopy (NSOM) forms images by scanning a sharp tip in close proximity to an object. The near-field profile is thus collected "point-by-point", which is a rather slow process that is incapable of projecting realtime images in the way lenses do. [5][6][7] Other techniques, based on nonlinear optical effects, have been proposed to improve resolution. 8 Recently, stimulated emission depletion fluorescence microscopy has emerged as one of the most successful techniques for subdiffraction-limited imaging, which cleverly uses saturation transitions between energy states of a fluorescence dye immersed in the object in shaping a subdiffraction spot. 9 However, this approach also requires time-consuming scanning of the object, in addition to the use of dyes and high illumination intensities to achieve the necessary nonlinear response. Recently, a remarkable perfect lens concept has been proposed that has the potential to recover lost evanescent information. 10 This is accomplished by coupling evanescent waves from the object to surface excitations on a slab of negative refractive index material. The lens compensates for evanescent wave decay in free space using the strong enhancement provided by the surface excitations, thereby restoring the evanescent components and projecting a perfect image. This effect has been studied for a wide range of frequencies in both composite metamaterials 11-14 and photonic band gap crystals. [15][16][17][18] Recently, optical superlensing has been successfully demonstrated using a silver 19 or SiC slab. 20 However, the superlenses experimentally demonstrated so far are only capable of projecting an image in the near field; due to the intrinsic losses, a simple slab superlens is "near-sighted". 21 Far-field imaging with a superlens still remains a great challenge to many exciting applications. In this Letter, we demonstrate a f...

Freely suspended nanocomposite layer‐by‐layer (LbL) nanomembranes composed of a central layer of gold nanoparticles sandwiched between polyelectrolyte multilayers are fabricated via spin‐assisted LbL assembly. The diameter of the circular membranes is varied from 150 to 600 μm and the thickness is kept within the range of 25–70 nm. The micro‐ and nanomechanical properties of these membranes are studied using a combination of resonance‐frequency and bulging tests, and point‐load nanodeflection experiments. Our results suggest that these freely suspended nanomembranes, with a Young's modulus of 5–10 GPa are very robust and can sustain multiple significant deformations. They are very sensitive to minor variations in pressure, surpassing ordinary semiconductor and metal membranes by three to four orders of magnitude and therefore have potential applications as pressure and acoustic microsensors.

Contrary to the conventional near-field superlensing, subwavelength superlens imaging is experimentally demonstrated in the far-field. The key element is termed as a Far-field SuperLens (FSL) which consists of a conventional superlens and a nanoscale coupler. The evanescent fields from the object are enhanced and then converted into propagating fields by the FSL. By only measuring the propagating field in the far-field, the object image can be reconstructed with subwavelength resolution. As an example of this concept, we design and fabricate a silver structured one dimensional FSL. Experimental results show that feature resolution of better than 50nm is possible using current FSL design.