Dielectric fluctuations underlie a wide variety of physical phenomena, from ion mobility in electrolyte solutions and decoherence in quantum systems to dynamics in glass-forming materials and conformational changes in proteins. Here we show that dielectric fluctuations also lead to noncontact friction. Using high sensitivity, custom fabricated, single crystal silicon cantilevers we measure ener...

We have developed the first high-diffraction-efficiency two-dimensional (2-D) photonic crystals for molecular recognition and chemical sensing applications. We prepared close-packed 2-D polystyrene particle arrays by self-assembly of spreading particle monolayers on mercury surfaces. The 2-D particle arrays amazingly diffract 80% of the incident light. When a 2-D array was transferred onto a hy...

Single-mode second-order distributed feedback (DFB) lasers with low threshold, based on polystyrene films doped with 30 wt. % of the hole-transporting organic molecule N,N'-bis (3-methylphenyl)-N,N'-diphenylbenzidine (TPD) are reported. The laser emission wavelength was tuned between 415 and 427 nm by film thickness variation. The effectiveness of the DFB grating in improving the laser performa...

Microfluidic devices composed of glass capillaries were used for generation of double emulsion droplets with photocurable shell phase. The cores of the emulsion droplets were aqueous suspension of higly charged polystyrene (PS) particles which readily form the crystals by repulsive interparticle potential. The shells of double emulsion droplets were solidified downstream and formed the polymeri...

Sphere segment void, or inverse opal, films prepared from a variety of coinage metals have shown promise as reliable and reproducible substrates for surface enhanced Raman spectroscopy (SERS). Sphere segment void substrates are prepared from colloidal templates consisting of one or more layers of polystyrene spheres. In this paper, we investigate the reflection spectra and SERS for a gold film ...