Opto-PCB: Three demonstrators for optical interconnections

We report on a research project targeting optical waveguide integrated PCBs conducted within the European FP6 Network of Excellence on Micro-Optics NEMO. For three identified feature requests we have built three specific demonstrators respectively addressing the integration of active components, the fabrication of peripheral fibre ribbons and the integration of multiple layers of waveguides on the board

Cucurbita plants: From farm to industry

The Cucurbita genus, a member of Cucurbitaceae family, also known as cucurbits, is native to the Americas. Genus members, like Cucurbita pepo and Cucurbita maxima, have been used for centuries in folk medicine for treating gastrointestinal diseases and intestinal parasites. These pharmacological effects are mainly attributed to their phytochemical composition. Indeed, Cucurbita species are a natural source of carotenoids, tocopherols, phenols, terpenoids, saponins, sterols, fatty acids, functional carbohydrates, and polysaccharides, that beyond exerting remarkable biological effects, have also been increasingly exploited for biotechnological applications. In this article, we specifically cover the habitat, cultivation, phytochemical composition, and food preservative abilities of Cucurbita plants.This work was supported by CONICYT PIA/APOYO CCTE AFB170007. N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

A combinatorial framework to quantify peak/pit asymmetries in complex dynamics

LL’s acknowledges funding from an EPSRC Early Career Fellowship EP/P01660X/1

Enhanced performance of pyroelectric microsensors through the introduction of nanoporosity

Sol-gel process has successfully been applied for the deposition of porous PbZrxTi1-xO3 (x = 0.45, 0.15) thin films on platinized silicon wafers. Addition of a polymer as a volatile phase to the precursor sol prior to spin coating has been proved an excellent method to synthesize PZT-porous films. Introduction of pores creates a matrix void composite resulting in high figures of merit for pyroelectric applications. The dielectric constant was found to be strongly dependent to the porosity, whereas the pyrocoefficient changes moderately with porosity. The relative permittivity can be decreased down to 150 and 95 for PZT films with Zr/Ti ratio of 45/55 and 15/85 respectively, and the figures of merit F-v and F-d values for PZT (Zr/Ti= 15/85) films can be increased up to 1.95 and 139 muC/m(2) K, respectively by incorporating a nanoporous structure in films. (C) 2003 Elsevier Ltd. All rights reserved

In-plane integration of polymer microfluidic channels with optical waveguides - a preliminary investigation

The next major challenges for lab-on-a-chip (LoC) technology are 1) the integration of microfluidics with optical detection technologies and 2) the large-scale production of devices at a low cost. In this paper the fabrication and characterisation of a simple optical LoC platform comprising integrated multimode waveguides and microfluidic channels based on a photo-patternable acrylate based polymer is reported. The polymer can be patterned into both waveguides and microfluidic channels using photolithography. Devices are therefore both quick and cost-effective to fabricate, resulting in chips that are potentially disposable. The devices are designed to be highly sensitive, using an in-plane direct excitation configuration in which waveguides intersect the microfluidic channel orthogonally. The waveguides are used both to guide the excitation light and to collect the fluorescence signal from the analyte. The potential of the device to be used for fluorescence measurements is demonstrated using an aqueous solution of sodium fluorescein. A detection limit of 7 nM is achieved. The possibilities offered by such a device design, in providing a cost-effective and disposable measurement system based on the integration of optical waveguides with LoC technology is discussed

Pyroelectric nanoporous films: Synthesis and properties

PbZrxTi1-xO3 (x=0.45) and PbxCa1-xTiO3 (PCT) (x=0.75) porous thin films were deposited on platinized silicon wafers by chemical solution deposition route using a polymer as a volatile phase. The introduction of pores creates a matrix-void composite resulting in a high figure of merit for pyroelectric applications. The figures of merit F-v and F-d for PCT films are shown to be as high as 4.8 and 250 muC/m(2) K, respectively. (C) 2002 American Institute of Physics

Properties of chemical solution deposited polycrystalline neodymium-modified Bi4Ti3O12

Thin films of neodymium-modified bismuth titanate Bi3.44Nd0.56Ti3O12 (BNT) were grown on Pt/TiO2/SiO2/Si substrates using chemical solution deposition method. The capacitors made by applying top Au electrodes on BNT films showed significantly improved values of the remanent polarization as compared to that using bismuth titanate Bi4Ti3O12 (BT) films. The 2P(r) value for the BNT capacitors was determined to be equal to 38 muC/cm(2) at an applied voltage of 24 V, whereas, for Bi4Ti3O12 ( BT) capacitors a value of 20 muC/cm(2) was measured at the same applied voltage. The maximum piezoelectric and pyroelectric coefficients of 22 pm/V and 112 muC/m(2) K respectively, were measured for the BNT thin films

Piezoelectric response and polarization switching in small anisotropic perovskite particles

A hydrothermal processing route was used to produce anisotropic submicrometer particles of potassium niobate-tantalates and pure potassium niobate. Piezoelectric activity, switching polarization, and piezoelectric hysteresis loops were observed in these ferroelectric perovskite nanorods by means of AFM assisted detection of induced piezoelectric vibrations. Both lattice and domain wall contributions to the piezoelectric response were evidenced

A Novel Single Step Sol Gel Process for Silica on Silicon Planar Lightwave Circuits

No abstract available