Application of plasma chemical treatment for manufacturing of instrument microstructures based on gallium nitride

The epitaxial layers of n-n+-GaN were processed by plasma-chemical etching using a Sentech SI 500 unit equipped with an inductively coupled plasma source. The regimes of gallium nitride processing in chlorine plasma have been established, which make it possible to remove epitaxial layers of the semiconductor down to a depth of 10 μm with a smooth surface. Based on the obtained processing results, prototype samples of Schottky diode microstructures with quasi-vertical contact geometry were manufactured. The effect of pretreatment on the characteristics of instrument microstructures is demonstrated.

Nanostructured versus flat compact electrode for triboelectric nanogenerators at high humidity

The triboelectric nanogenerator (TENG) is a promising technology for mechanical energy harvesting. TENG has proven to be an excellent option for power generation but typically TENGs output power drops significantly in humid environments. In this work, the effect of electrode’s material on power output, considering smooth and nanostructured porous structures with various surface hydrophobicity, is investigated under various humidity conditions. A vertical contact-separation mode TENG is experimentally and numerically studied for four surface morphologies of Ti foil, TiO2 thin film, TiO2 nanoparticulated film, and TiO2 nanotubular electrodes. The results show that the TENG electrical output in the flat structures such as Ti foil and TiO2 thin film at 50% RH is reduced to 50% of its initial state, while in the nanoporous structures such as nanoparticle and nanotube arrays, this is observed at RH above 95%. The results show that the use of porous nanostructures in TENG due to their high surface-to-volume, and that the process of water adsorption on the pore leads to better performance than the flat surface in humid environments. Based on our study, employing nanoporous layers is vital for nanogenerators either for power generation or active sensor applications at high humidity conditions.

Triangulated Cylinder Origami-Based Piezoelectric/Triboelectric Hybrid Generator to Harvest Coupled Axial and Rotational Motion

Piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs) are representative technologies that can harvest mechanical energy. In general, piezoelectric/triboelectric hybrid generators can harvest considerable energy with a limited input; however, PENGs and TENGs entail different requirements for harvesting energy. Specifically, PENGs produce a large output when a large mechanical strain is applied, and TENGs require a large surface area to produce a high power. Therefore, it is necessary to develop an innovative strategy in terms of the structural design to satisfy the requirements of both PENGs and TENGs. In this study, we developed a triangulated cylinder origami-based piezoelectric/triboelectric hybrid generator (TCO-HG) with an origami structure to enable effective energy harvesting. The proposed structure consists of a vertical contact-separation TENG on the surface of the triangulated cylinder, PENG on the inner hinge, and rotational TENG on the top substrate to harvest mechanical energy from each motion. Each generator could produce a separate electrical output with a single input. The TCO-HG could charge a 22 μF commercial capacitor and power 60 LEDs when operated.

3D Ionic Networked Hydrophilic-Hydrophobic Nano Channeled Triboelectric Nanogenerators

The power demand is increasing day by day owing to the diminishing of fossil fuel reserves on the globe. To overcome the future energy crises, there is a strong need to fulfill the energy loophole by novel technologies such as triboelectric nanogenerators to harvest miniature resources from renewable natural resources. Here, I discussed the synthesis and fabrication of novel triboelectric nanogenerators (TENGs) using highly reproducible power generators as electropositive surfaces from the monomers of naphthalene tetracarboxylic dianhydride, benzdiene diamine, and sulfonated polyimide (Bno-Spi), and modified nonwoven carbon fibers (Wcf) and polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF) as electronegative TENG electrodes, respectively. Here, novel double characteristic hydrophilic and hydrophobic nano-channels concerned with Bno-Spi films were proposed through contact electrification process through ion and electron transfer by an electron-donor-acceptor complex mechanism. The proposed Bno-Spi-TENG system High triboelectric open circuit voltage 75 V (Voc) and short circuit current 1 μA (Jsc) have been achieved from Bno-Spi-TENGs, in particular, and for SO3H.Bno-Spi-TENG at 6 Hz. Besides that, we used improved knitted woven carbon fiber composite (wcf-COOH), as one of the TENGs to generate a greater open-circuit voltage (Voc), and short circuit current (Isc). Also, I aimed the contact and separation mode TENG which is using spring structure through oxidation of Wcf into Wcf-COOH followed by coupling of aniline through and one-step oxidative polymerization to get woven carbon fiber-polyaniline emraldine salt (Wcf-Pani.Es). The Wcf-PANI.Es composite film (thickness ~ 100 nm) shows the surface resistivity of 0.324 Ω m, and functions as a rubbing surface to produce charges through harvesting of energy using vertical contact-separation mode TENG. The vibrant exchanges of novel Wcf-Pani.Es, and PVDF membrane produced higher Voc of 95 V, and Isc of 180 μA, correspondingly. In specific, Wcf-Pani.Es -TENG is shown an enhancement of 498% of Voc concerning Wcf-COOH-TENG due to the availability of the Pani.Es layer. The novel Bno-Spi-TENGs and Wcf-Pani.Es are the potential candidates for fulfilling the need for improved energy harvesting devices as an alternate substantial choice for contact-separation mode TENGs.

Use of Geophysical and Radar Interferometric Techniques to Monitor Land Deformation Associated with the Jazan Salt Diapir, Jazan city, Saudi Arabia

Using integrated Interferometric Synthetic Aperture Radar (InSAR) datasets (Envisat: 2003–2009; Sentinel-1: 2014–2018), local gravity surveys, and passive seismic data, we investigated the environmental hazards associated with the rise of the Miocene Jazan salt diapir (JZD; ~ 2 km2) within Jazan city, Saudi Arabia, and identified areas at risk in its immediate surroundings. Our findings include (1) the JZD outcrop and its northern, southern and western bordering areas have been undergoing substantial uplift (up to 4.7 mm/yr), whereas the sabkhas to the east are witnessing subsidence (up to − 7.5 mm/yr); (2) a low Bouguer anomaly (7.5 mGal) was observed over the JZD relative to its surroundings (8.5–12 mGal) with the steepest gradient along its eastern side; (3) strong and clear horizontal/vertical (H/V) spectral ratio peak and high frequency (5–10 Hz) over the JZD outcrop and areas proximal to its western margin, but areas to the east have a weak H/V peak and low frequency (1.5-3 Hz); (4) drilling confirmed presence of a shallow (4 m) salt bedrock layer west of the JZD and the absence of this layer to its east (up to depths of 60 m); (5) uplift patterns along the diapir margins are indicative of near-vertical contact along the JZD eastern margin and less steep contacts along the remaining margins; and (6) additional near-surface diapirs could potentially be identified in the vicinity of the JZD using our integrated approach.