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The rediscovery of temperature-controlled self-faceting, shaping, and splitting transitions in liquid oil-in-water emulsion droplets, has recently led to a significant progress in the fundamental understanding of these counterintuitive phenomena, sparking scientific controversies, and opening new routes towards their technological applications. These recent developments are reviewed here. The faceting transitions were demonstrated to occur in a wide range of oil:surfactant combinations, for broad temperature ranges, and in droplets of sizes spanning an incredible 13 decades in volume, from nano ( 11 × 10 − 9 ) to yocto ( 300 × 10 − 24 ) liters. Droplets' polymerization enables forming solid faceted particles, of shapes and sizes otherwise unachievable. Colloids and nanoparticles adsorbed controllably onto the faceted liquid droplets' interfaces self-position at their vertices and self-expel into the aqueous medium. The self-positioning enables droplets’ decoration by precisely positioned functional ligands, paving the way for directed self-assembly of multiparticle structures for a wide range of microtechnological and nanotechnological applications.

High-Ni-rich layered oxides [e.g., LiNi

Dense wavelength division multiplexers are key components of data communication networks. This paper presents a silicon-photonic eight-channel multiplexer device with a channel spacing of only 0.133 nm (17 GHz). Devices were fabricated in a commercial silicon foundry, in 8" silicon-on-insulator wafers. The device layout consists of seven unbalanced Mach–Zehnder interferometers in a cascaded tree topology, and each interferometer unit also includes a nested ring resonator element. The transfer function of each unit is that of a maximally flat, auto-regressive, moving-average filter. The devices are characterized by uniform passbands, sharp spectral transitions between pass and stop bands, and strong out-of-band rejection. The worst-case optical power crosstalk is −22 dB. The proper function of the device requires careful control of optical phase delays over 14 distinct optical paths. Post-fabrication trimming of phase delays was performed through local illumination of a photo-sensitive upper cladding layer of chalcogenide glass. The de-multiplexing of three adjacent QAM-16, 40 Gbit/s wavelength-division channels was successfully demonstrated. The devices are applicable in data communication and in integrated-photonic processing of radio-over-fiber waveforms.

Laser-induced forward transfer (LIFT) has been shown to be a useful technique for the manufacturing of micron-scale metal structures. LIFT is a high-resolution, non-contact digital printing method that can support the fabrication of complex shapes and multi-material structures in a single step under ambient conditions. However, LIFT printed metal structures often suffer from inferior mechanical, electrical, and thermal properties when compared to their bulk metal counterparts, and often are prone to enhanced chemical corrosion. This is due mostly to their non-compact structures, which have voids and inter-droplet delamination. In this paper, a theoretical framework together with experimental results of achievable compactness limits is presented for a variety of metals. It is demonstrated that compactness limits depend on material properties and jetting conditions. It is also shown how a specific choice of materials can yield compact structures, for example, when special alloys are chosen along with a suitable donor construct. The example of printed amorphous ZrPd is detailed. This study contributes to a better understanding of the limits of implementing LIFT for the fabrication of metal structures, and how to possibly overcome some of these limitations.

Production of multilayered microstructures composed of conducting and insulating materials is of great interest as they can be utilized as microelectronic components. Current proposed fabrication methods of these microstructures include top-down and bottom-up methods, each having their own set of drawbacks. Laser-based methods were shown to pattern various materials with micron/sub-micron resolution; however, multilayered structures demonstrating conducting/insulating/conducting properties were not yet realized. Here, we demonstrate laser printing of multilayered microstructures consisting of conducting platinum and insulating silicon oxide layers by a combination of thermally driven reactions with microbubble-assisted printing. PtCl2 dissolved in N-methyl-2-pyrrolidone (NMP) was used as a precursor to form conducting Pt layers, while tetraethyl orthosilicate dissolved in NMP formed insulating silicon oxide layers identified by Raman spectroscopy. We demonstrate control over the height of the insulating layer between ∼50 and 250 nm by varying the laser power and number of iterations. The resistivity of the silicon oxide layer at 0.5 V was 1.5 × 1011 Ωm. Other materials that we studied were found to be porous and prone to cracking, rendering them irrelevant as insulators. Finally, we show how microfluidics can enhance multilayered laser microprinting by quickly switching between precursors. The concepts presented here could provide new opportunities for simple fabrication of multilayered microelectronic devices.

Similarly to other transition metal sulfides, nickel sulfide nanocrystals can be potentially used for functional device applications. However, controlling morphology and stoichiometry to target specific applications is a synthesis challenge. In this work we developed a rapid, one-step, chemical vapor deposition synthesis of nickel sulfide dendritic nanostructures with fractal geometry. Microtome-EDS compositional analysis of the mature crystal indicates a trend of decreasing sulfur and increasing nickel concentration towards the tip of the mature crystals. Following thorough investigation of these nanocrystals at different stages of their nucleation and growth by means of XRD, HR-SEM, HR-TEM, and Raman spectroscopy, we suggest possible kinetic mechanisms for the crystal formation and development. This work contributes to the understanding of growth mechanisms of dendritic structures with complex morphology.

In continuation of the work on the stabilization of the electrochemical performance of Li and Mn‐rich LixNiyCozMnwO2 (HE‐NCM, x > 1, w > 0.5, x + y + z + w = 2) cathode materials via atomic layer deposition (ALD) surface coatings, herein, the active role of aluminum oxides‐based coatings, during prolonged cycling in battery prototypes with graphite anodes, is discussed. Notable progress in electrochemical cycling and rate performance of Na‐aluminate‐coated Li1.142Mn0.513Ni0.230Co0.115O2 cathode material is established. These coated electrodes delivered a stable discharge capacity of 145 mAh g−1 (66% retention), compared to only 118 mAh g−1 (55% retention) for the uncoated sample at a 1.0 C rate after 400 cycles. Steady average discharge potential, lower voltage hysteresis, and stable energy density profiles are the noteworthy achievements for the coated material during cycling. Significant improvement in the coated material's thermal stability compared with the uncoated one has also been confirmed. The present study also enlightens about the Na‐aluminate coating's orientation and distribution on HE‐NCM material's surface. 23Na and 27Al solid‐state nuclear magnetic resonance (NMR) studies reveal the Na‐aluminate coating's crystalline constituent's disappearance upon cycling. The partial dissolution of Na5AlO4 coating, followed by forming a secondary disordered edge‐site phase that remains even after long‐term cycling, is disclosed.

Thousands of specialized, steroidal metabolites are found in a wide spectrum of plants. These include the steroidal glycoalkaloids (SGAs), produced primarily by most species of the genus Solanum, and metabolites belonging to the steroidal saponins class that are widespread throughout the plant kingdom. SGAs play a protective role in plants and have potent activity in mammals, including antinutritional effects in humans. The presence or absence of the double bond at the C-5,6 position (unsaturated and saturated, respectively) creates vast structural diversity within this metabolite class and determines the degree of SGA toxicity. For many years, the elimination of the double bond from unsaturated SGAs was presumed to occur through a single hydrogenation step. In contrast to this prior assumption, here, we show that the tomato GLYCOALKALOID METABOLISM25 (GAME25), a short-chain dehydrogenase/reductase, catalyzes the first of three prospective reactions required to reduce the C-5,6 double bond in dehydrotomatidine to form tomatidine. The recombinant GAME25 enzyme displayed 3β-hydroxysteroid dehydrogenase/Δ5,4 isomerase activity not only on diverse steroidal alkaloid aglycone substrates but also on steroidal saponin aglycones. Notably, GAME25 down-regulation rerouted the entire tomato SGA repertoire toward the dehydro-SGAs branch rather than forming the typically abundant saturated α-tomatine derivatives. Overexpressing the tomato GAME25 in the tomato plant resulted in significant accumulation of α-tomatine in ripe fruit, while heterologous expression in cultivated eggplant generated saturated SGAs and atypical saturated steroidal saponin glycosides. This study demonstrates how a single scaffold modification of steroidal metabolites in plants results in extensive structural diversity and modulation of product toxicity.

A biosensor for ammonia is developed aimed at detecting the presence of H. pylori bacteria in gastric fluids. The sensor is based on a GaAs device coated with a unique functional polymer that enables high device sensitivity to low concentrations of ammonia and long-term protection in harsh environments. The detection of ammonia in gastric fluids taken from patients is possible by covering the device with a dialysis membrane, thus enabling the diffusion of only small molecules to the sensing area, while preventing agglomeration of macromolecules on the surface of the device. The mechanism by which ammonia is detected is investigated and an analytical expression is provided relating the response of the detector to the ammonia concentration and the pH of the solution.

We review some of the sensors based on the molecular control semiconductor resistor (MOCSER) technology. The technology can be applied for developing highly sensitive and selective molecular sensors that operate both in gas and in liquid environments. Specifically, we describe here a set of GaAs gas-phase sensors based on an array constructed from several elements, each coated with a different sensing molecule. Coating the same semiconductor device with an ultrathin polymer layer also allows the use of the device in a harsh liquid environment and in performing measurements in physiological liquids. Hence, the MOCSER-based platform opens the way for producing inexpensive, easy to use, and robust sensors for a wide variety of applications.

Microelectronic-based sensors are ideal for real-time continuous monitoring of health states due to their low cost of production, small size, portability, and ease of integration into electronic systems. However, typically semiconductor-based devices cannot be operated in aqueous solutions, especially in solutions with a low pH. However, in this work we overcame this difficulty and demonstrated the feasibility of a hemoglobin sensing array based on hybrid organic GaAs-based devices, which can remain in biological solutions for more than 24 h. This was achieved by coating devices with a nanometer-thick polymer protective layer with subsequent adsorption of antibodies on its surface. The device is capable of functioning even in harsh physiological fluids, such as urine and bile juice. The surface modification allows a change in electrical potential, created by the interaction, to be efficiently transferred to the surface of the semiconductor device. By utilizing an array configuration, it is possible to obtain high sensitivity and selectivity.

The detection of covalent and noncovalent binding events between molecules and biomembranes is a fundamental goal of contemporary biochemistry and analytical chemistry. Currently, such studies are performed routinely using fluorescence methods, surface-plasmon resonance spectroscopy, and electrochemical methods. However, there is still a need for novel sensitive miniaturizable detection methods where the sample does not have to be transferred to the sensor, but the sensor can be brought into contact with the sample studied. We present a novel approach for detection and quantification of processes occurring on the surface of a lipid bilayer membrane, by monitoring the current change through the n-type GaAs-based molecularly controlled semiconductor resistor (MOCSER), on which the membrane is adsorbed. Since GaAs is susceptible to etching in an aqueous environment, a protective thin film of methoxysilane was deposited on the device. The system was found to be sensitive enough to allow monitoring changes in pH and in the concentration of amino acids in aqueous solution on top of the membrane. When biotinylated lipids were incorporated into the membrane, it was possible to monitor the binding of streptavidin or avidin. The device modified with biotin-streptavidin complex was capable of detecting the binding of streptavidin antibodies to immobilized streptavidin with high sensitivity and selectivity. The response depends on the charge on the analyte. These results open the way to facile electrical detection of protein-membrane interactions.