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This paper presents the design, fabrication, and characterization of a novel inclination-angle sensor (inclinometer) using heating and sensing elements based on conductive polydimethylsiloxane (PDMS) composited with carbon nanotubes (CNTs). The inclinometer consists of a PDMS cube-shaped chamber, a CNTs/PDMS composite-based heater, and four CNTs/PDMS composite-based temperature sensors. The working mechanism of this sensor is based on thermal convective sensing theory on the basis of the detection of thermal disturbance caused by inclination-induced convection in a sealed chamber. In order to prepare the conductive CNTs/PDMS composite, toluene was applied as a solvent to facilitate CNT dispersion in PDMS matrix and then was removed by evaporation. The resistive heating and thermal sensing properties of CNT/PDMS composite-based elements were tested and analyzed first. Then, the responses to inclination-angle were monitored and reported. Experimental results demonstrate that the inclinometer can measure dual-axis angular position in the range of 360° with high stability and repeatability. [ABSTRACT FROM AUTHOR]

An intertwined single-walled carbon nanotubes (SWCNTs)/carbothermal ZnO nanowires (ZNWs) composite is synthesized using a facile ultrasonic stirring technology, which is deposited on Au-interdigitated electrodes for ultraviolet-visible (UV-Vis) photoresponse enhancement. It is found that the SWCNT attached on ZNW surface optimizes the surface-related chemical processes and provides effective carrier transport strategies, responsible for the improvement in photo-responsivity and photo-sensing speed. The UV-Vis absorption of ZNWs has been improved after compositing with the high-conductive SWCNTs, contributing to the significantly improved photo-conductance. The photodetector based on SWCNT/ZNW composites (CZWs) with an optimal SWCNT content of 0.1 wt% shows a 300% improvement in photocurrent density, a 200% improvement in responsivity, and a 400% improvement in on/off current ratio over the pure ZNWs-based device under a UV irradiation of 3.26 mW cm−2 and a bias voltage of 1.0 V. This synthetic method could be scaled up for large-scale fabrication of CZWs on substrate at low cost for practical photodetecting applications. [ABSTRACT FROM AUTHOR]

The polyyttriocarbosilane (PYCS) with various quantities of yttrium was obtained by reacting yttrium acetylacetonate (Y(AcAc)) with polycarbosilane (PCS). The molecular weight, softening point, and Si-H bond content of the resulting PYCS are controlled by the Y(AcAc):PCS weight ratio, reaction temperature and reaction time. The main chain of the PYCS is made up of alternating carbon and silicon atoms with small amount of Si-O-Y presented in the main chain and Si-H groups at the side chain. The pyrolysis process of PYCS was investigated by TG and XRD. The results reveal that the polymer-to-ceramic transition of the PYCS occurs in three steps. The final ceramics obtained at 1,800 °C contain a large number of β-SiC crystallites and a small amount of α-SiC crystallites. [ABSTRACT FROM AUTHOR]

This paper presents the design, fabrication, and characterization of a middle-infrared (MIR) linear variable optical filter (LVOF) and thermopile detectors that will be used in a miniaturized mixed gas detector for CH4/CO2/CO measurement. The LVOF was designed as a tapered-cavity Fabry-Pérot optical filter, which can transform the MIR continuous spectrum into multiple narrow band-pass spectra with peak wavelength in linear variation. Multi-layer dielectric structures were used to fabricate the Bragg reflectors on the both sides of tapered cavity as well as the antireflective film combined with the function of out-of-band rejection. The uncooled thermopile detectors were designed and fabricated as a multiple-thermocouple suspension structure using micro-electro-mechanical system technology. Experimentally, the LVOF exhibits a mean full-width-at-half-maximum of 400 nm and mean peak transmittance of 70% at the wavelength range of 2.3~5 μm. The thermopile detectors exhibit a responsivity of 146 μV/°C at the condition of room temperature. It is demonstrated that the detectors can achieve the quantification and identification of CH4/CO2/CO mixed gas. [ABSTRACT FROM AUTHOR]