Contamination-insensitive differential capacitive pressure sensors

In this paper, a contamination-insensitive differential capacitive pressure sensor with a sealed gap is presented. This device is made of three polysilicon layers including a stationary middle plate and the top and bottom plates that are rigidly coupled together by a series of posts hence deflecting in tandem by a change in differential or gauge pressure. Because of the posts, however, the device is insensitive to common-mode pressure. As the differential pressure is changed from -70 to 70 kPa, the capacitance between the bottom and middle plates changes by 73 fF (sensitivity of approximately 0.5 fF/kPa), yet there is only a 2-fF change in output when the common-mode pressure is changed from 30 to 200 kPa. The devices have a linearity error on the order of -15% FSS and a temperature coefficient of offset of 170 ppm/°C     

Effect of nanoclay on the properties of rosin derivative cross-linked green composite based on chicken feather fiber and modified vegetable oil

Fully biodegradable composites based on waste chicken feather fiber (CF), functionalized epoxidized soybean oil (ESO), rosin derivative and various nanoclay percentages were prepared via compression molding. Rosin derivative was synthesized as a substitute of styrene/divinylbenzene. Nuclear magnetic resonance and Fourier transform infrared spectroscopy confirmed the synthesized rosin derivatives structures. Delamination and distribution of silicate layers were studied by X-ray diffraction and transmission electron microscopy. Scanning electron microscopy was used to analyse compatibility among modified ESO and rosin. FTIR study revealed the interaction between resin, CF, rosin derivative, and nanoclay. The nanoclay loaded composites showed better mechanical properties than the nanoclay free composite. The thermal stability of nanoclay loaded composites were also found to be enhanced. Composites loaded with nanoclay (3 wt%) revealed the least chemical resistance, volumetric swelling and water vapor uptake capacity.     

Structural and optical studies on hot wire chemical vapour deposited hydrogenated silicon films at low substrate temperature

Thin films of hydrogenated silicon are deposited by hot wire chemical vapour deposition technique, as an alternative of plasma enhanced chemical vapour deposition technique. By varying the hydrogen and silane flow rate, we deposited the films ranging from pure amorphous to nanocrystallite-embedded amorphous in nature. In this paper we report extensively studied structural and optical properties of these films. It is observed that the rms bond angle deviation decreases with increase in hydrogen flow rate, which is an indication of improved order in the films. We discuss this under the light of breaking of weak Si-Si bonds and subsequent formation of strong Si-Si bonds and coverage of the growing surface by atomic hydrogen.     

Thermally deposited Ag-doped CdS thin film transistors with high-k rare-earth oxide Nd2O3 as gate dielectric

The performance of thermally deposited CdS thin film transistors doped with Ag has been reported. Ag-doped CdS thin films have been prepared using chemical method. High dielectric constant rare earth oxide Nd₂O₃ has been used as gate insulator. The thin film trasistors are fabricated in coplanar electrode structure on ultrasonically cleaned glass substrates with a channel length of 50 μm. The thin film transistors exhibit a high mobility of 4.3 cm² V^?1 s^?1 and low threshold voltage of 1 V. The ON-OFF ratio of the thin film transistors is found as 10⁵. The TFTs also exhibit good transconductance and gain band-width product of 1.15 × 10^?3 mho and 71 kHz respectively.     

Synergistic effect of nanoTiO2 and nanoclay on mechanical, flame retardancy, UV stability, and antibacterial properties of wood polymer composites

Wood–polymer nanocomposite (WPNC) based on styrene–acrylonitrile copolymer (SAN), γ-trimethoxy silyl propyl methacrylate-modified TiO₂ nanoparticles, and nanoclay was prepared by impregnation. The flexural, tensile, and flame-retardant properties were improved. UV stability was evaluated by photo-induced weight loss, FTIR, loss in mechanical properties, and scanning electron microscopy. The results showed that UV stability was maximum for wood sample treated with SAN/TiO₂ (0.5 %)/nanoclay (0.5 %). The presence of TiO₂ nanoparticles in WPNC-exhibited antibacterial activity.     

Electrochemical behaviour of LaCl3 at tungsten and aluminium cathodes in LiCl–KCl eutectic melt

The electrochemical behaviour of lanthanum was studied at inert tungsten electrode and reactive aluminium electrode in LiCl–KCl eutectic melt in the temperature range 698–798 K using transient electrochemical techniques. Reduction of La(III) to La(0) at the tungsten electrode takes place in a single step. The reduction shows quasi-reversible behaviour for polarization rates, 25 ≤ ν ≤ 150 mV s^?1 and is predominantly controlled by charge transfer of La(III) ions for scan rates higher than 75 mV s^?1. The heterogenous rate constant of the process was estimated from impedance spectroscopy and from the semi-integrals of the cyclic voltammograms. The redox potential of the La(III)/La couple at the Al electrode was observed to be more positive than that at the inert electrode. This potential shift is due to the lowering of the activity of La in the metal phase caused by the formation of the intermetallic compound Al₁₁La₃. Thermodynamic properties such as Gibbs energy of formation of Al₁₁La₃, excess Gibbs energy and the activity coefficient of La in Al were calculated from the open circuit potential measurement.     

Structural Exploration of (3S,6S)‐6‐Benzhydryl‐N‐benzyltetrahydro‐2H‐pyran‐3‐amine Analogues: Identification of Potent Triple Monoamine Reuptake Inhibitors as Potential Antidepressants

To further explore the basic structural motifs (3S,6S)‐6‐benzhydryl‐N‐benzyltetrahydro‐2H‐pyran‐3‐amine and (2S,4R,5R)‐2‐benzhydryl‐5‐(benzylamino)tetrahydro‐2H‐pyran‐4‐ol, developed by our research group, for monoamine transport inhibition, we designed and synthesized various structurally altered analogues. The new compounds were tested for their affinities for the dopamine transporter (DAT), the serotonin transporter (SERT), and the norepinephrine transporter (NET) in rat brain by measuring their capacity to inhibit the uptake of [³H]DA, [³H]5‐HT, and [³H]NE, respectively. Our results point to novel compounds with a TUI, DNRI, SNRI, or SSRI profile. Among the TUIs, compound 2 g exhibited a balanced potency for all three monoamine transporters (K_i: 60, 79, and 70.3 nM for DAT, SERT, and NET, respectively). In the rat forced swim test, compound 2 g produced a significant decrease in immobility in drug‐treated rats relative to vehicle, indicating a potential antidepressant property.     

Elimination of post-release adhesion in microstructures usingconformal fluorocarbon coatings

The adhesion of polysilicon microstructures to their substrates is eliminated using a relatively conformal hydrophobic fluorocarbon (FC) coating grown in a field-free zone of a plasma reactor. Experiments show that the FC film deposition on top of the microstructure and on the underside was approximately 2:1. The FC coating is able to cover the entire underside of a 200×200 μm² plate, with a 20% deposition nonuniformity. The coating exhibits a contact angle of 110° and is able to prevent adhesion of cantilever beams and doubly supported beams to their substrates even after direct immersion in DI water. The durability of the coating was tested using an accelerated aging method, predicting a lifetime of greater than ten years at 150°C. Periodic wear tests indicate that the coating remains hydrophobic even after 10⁷ contact cycles