Search Results (14)

The opto-mechanical automated manufacturing process, characterized by stringent process constraints, dynamic disturbances, and conflicting optimization objectives, presents significant control challenges for traditional scheduling and control approaches. We formulate the scheduling problem within a closed-loop control paradigm and propose a novel bi-level intelligent control framework integrating Deep Reinforcement Learning (DRL) and Bayesian Optimization (BO). The core of our approach is a bi-level intelligent control framework. An inner DRL agent acts as an adaptive controller, generating control actions (scheduling decisions) by perceiving the system state and learning a near-optimal policy through a carefully designed reward function, while an outer BO loop automatically tunes the DRL’s hyperparameters and reward weights for superior performance. This synergistic BO-DRL mechanism facilitates intelligent and adaptive decision-making. The proposed method is extensively evaluated against standard meta-heuristics, including Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), on a complex 20-jobs × 20-machines flexible job shop scheduling benchmark specific to opto-mechanical automated manufacturing. The experimental results demonstrate that our BO-DRL algorithm significantly outperforms these benchmarks, achieving reductions in makespan of 13.37% and 25.51% compared to GA and PSO, respectively, alongside higher machine utilization and better on-time delivery. Furthermore, the algorithm exhibits enhanced convergence speed, superior robustness under dynamic disruptions (e.g., machine failures, urgent orders), and excellent scalability to larger problem instances. This study confirms that integrating DRL’s perceptual decision-making capability with BO’s efficient parameter optimization yields a powerful and effective solution for intelligent scheduling in high-precision manufacturing environments. Full article

Transient receptor potential canonical 6 (TRPC6) channels are promising drug targets for kidney, lung, and neurological diseases, making a detailed understanding of their regulation crucial to developing novel channel modulators with more precise modes of action. TRPC6 channels are commonly accepted as calcium-permeable, receptor-operated cation channels activated by diacylglycerol (DAG) downstream of phospholipase C (PLC) signaling. DAG, the endogenous activator of TRPC channels, also activates protein kinase C (PKC), which can phosphorylate TRPC6 and potentially modify its function. This study examined whether five putative PKC phosphorylation sites located in the C-terminus of TRPC6 affect channel gating. Using whole-cell patch-clamp recordings and utilizing photopharmacology with photoswitchable TRPC6 activators (OptoBI-1 and OptoDArG), we analyzed the activation, inactivation, and deactivation kinetics. Pharmacological modulation of PKC activity and strategic mutation of the phosphorylation sites—either to prevent or mimic phosphorylation—altered the current kinetics as well as the normalized slope conductances that were used to quantify differences in the curve progression of current–voltage relations, even when maximally induced current density amplitudes were unchanged. Our findings reveal activator-specific differences in TRPC6 current kinetics associated with C-terminal amino acid exchanges and PKC-dependent signaling, suggesting that phosphorylation-related mechanisms may fine-tune channel activity. Full article

Two-dimensional (2D) materials are regarded as key foundational materials for next-generation optoelectronic devices. As a promising new type of 2D layered semiconductor, Bi₂O₂Se has emerged as a strong candidate for high-performance opto-electronic devices due to its high carrier mobility, tunable bandgap, and excellent environmental stability. However, achieving precise control over Bi₂O₂Se growth to obtain high-quality Bi₂O₂Se remains a challenge in the field. In this study, we employed chemical vapor deposition (CVD) to grow thin-layer 2D Bi₂O₂Se flakes. We further used a transport model and thermodynamic Arrhenius fitting to analyze the relationship between vapor flux and the properties of the flakes. Density functional theory was used to study the electronic structure of the as-grown samples. The electrical and optoelectronic results demonstrate that Bi₂O₂Se-based FETs exhibit good performance in terms of mobility (129 cm²V⁻¹s⁻¹), on/off ratio (4.51 × 10⁵), and photoresponsivity (94.98 AW⁻¹). This work provides a new way to study the influence of vapor flux on the sizes and shapes of Bi₂O₂Se flakes for photodetectors. Full article

Coordination-driven Cu(I) complexes constitute an interesting class of materials with rich opto-electronic properties and diverse applications. Various homo- and heteroleptic Cu(I) complexes have been reported in the literature. In continuation with our quest for new materials, we report herein two novel coordination-driven self-assembled Cu(I) complexes: the homoleptic (1) and the heteroleptic (2) complexes based on the 6,6′-bis(phenylethynyl)-2,2′-bipyridine (L1) and 2,9-dimethyl-1,10-phenanthroline (dmph) ligands. L1 was prepared by a Pd(II)-catalyzed Sonogashira cross-coupling reaction between phenylactylene and 6,6′-dibromo-2,2′-bipyridine. Homo- and heteroleptic Cu(I) complexes were obtained by the self-assembly of L1 and dmph ligands. Complexes (1) and (2) were obtained in high yields, and are soluble in common organic solvents and stable at room temperature over a long period of time. The optical (absorption and emission) properties of both complexes were evaluated. The optical properties in solution are a function of the ligands and varied for the complexes. Complex (2) was also characterized by single-crystal X-ray diffraction and the intermolecular interaction was studied using Hirschfeld surface analysis. In the solid state, complex (2) exhibited four-coordinate distorted tetrahedral geometry around Cu(I). Density functional theory (B3LYP/6-311++G(d,p) was utilised to determine various molecular descriptors. Full article

The purpose of this research work was to synthesis bioderived nanocomposite films by incorporating Na_0.5Bi_0.5TiO₃ (NBTO) nanoparticles into a chitosan matrix. The NBTO nanoparticles were synthesized using a traditional solid-state technique. Then, through a solution-casting approach, flexible composite films were fabricated using chitosan polymer. The study presents a range of compelling findings. For structural and morphological insights, scanning electron microscopy (SEM) reveals a fascinating morphology where NBTO nanoparticles are uniformly dispersed and interlocked with other particles, forming interconnected grains with significant interspaces within the chitosan matrix. For the optical properties, the spectral response within the 300–800 nm range is primarily governed by light scattering attributed to NBTO particles with diameter sizes ranging from 100 to 400 nm, as well as the distinctive bandgap exhibited by the NBTO phase. The investigation of dielectric properties demonstrates that composite films exhibit markedly higher dielectric values in comparison to pure chitosan films. It is noteworthy that an increase in the NBTO content results in a corresponding increase in dielectric values, enhancing the versatility of these materials. Local piezoelectric measurements utilizing piezoresponse force microscopy confirm the expected piezoelectric and ferroelectric behavior of NBTO particles when dispersed within the chitosan matrix. This research introduces a novel class of biocompatible nanocomposite materials, combining impressive structural attributes, enhanced dielectric properties, and piezoelectric capabilities. The outcomes of this study hold substantial promise for advanced applications in opto- and piezoelectric technologies, marking a significant advancement in biologically sourced materials with multifunctional properties. Full article

Wider application of BiVO₄ (BVO) for photocatalytic water treatment is primarily limited by its modest photocatalytic effectiveness, despite its appropriately narrow band gap for low-cost, sunlight-facilitated water treatment processes. In this study, we have photomodified an isotype BVO, consisting of a tetragonal zircon and monoclinic scheelite phase, with Fe (Fe@BVO) and Ag (Ag@BVO) ionic precursors under UV illumination in an aqueous ethanol solution in order to assess their effect on the opto-electronic properties and effectiveness for the removal of ciprofloxacin (CIP). Fe@BVO failed to demonstrate enhanced effectiveness over pristine BVO, whereas all Ag@BVO achieved improved CIP degradation, especially 1% Ag@BVO. At pH 4 and 6, 1% Ag@BVO demonstrated nearly 24% greater removal of CIP than BVO alone. Photomodification with Fe created surface oxygen vacancies, as confirmed by XPS and Mott–Schottky analysis, which facilitated improved electron mobility, although no distinct Fe-containing phase nor Fe-doping was detected. On the other hand, the introduction of mid-band gap states by oxygen vacancies decreased the reducing power of the photogenerated electrons as the flat band potentials were shifted to more positive values, thus likely negatively impacting superoxide formation. In contrast, Ag-photomodification (Ag@BVO) resulted in the formation of Ag₂O/AgO and Ag nanoparticles on the surface of BVO, which, under illumination, generated hot electrons by surface plasmon resonance and enhanced the mobility of photogenerated electrons. Our research underscores the pivotal role of photogenerated electrons for CIP degradation by BiVO₄-based materials and emphasizes the importance of appropriate band-edge engineering for optimizing contaminant degradation. Full article

It is a great challenge to develop low-cost and dopant-free polymer hole-transporting materials (HTM) for PSCs, especially for efficient air-processed inverted (p-i-n) planar PSCs. A new homopolymer HTM, poly(2,7-(9,9-bis(N,N-di-p-methoxylphenyl amine)-4-phenyl))-fluorene (denoted as PFTPA), with appropriate photo-electrochemical, opto-electronic and thermal stability, was designed and synthesized in two steps to meet this challenge. By employing PFTPA as dopant-free hole-transport layer in air-processed inverted PSCs, a champion power conversion efficiency (PCE) of up to 16.82% (0.1 cm²) was achieved, much superior to that of commercial HTM PEDOT:PSS (13.8%) under the same conditions. Such a superiority is attributed to the well-aligned energy levels, improved morphology, and efficient hole-transporting, as well as hole-extraction characteristics at the perovskite/HTM interface. In particular, these PFTPA-based PSCs fabricated in the air atmosphere maintain a long-term stability of 91% under ambient air conditions for 1000 h. Finally, PFTPA as the dopant-free HTM was also fabricated the slot-die coated perovskite device through the same fabrication condition, and a maximum PCE of 13.84% was obtained. Our study demonstrated that the low-cost and facile homopolymer PFTPA as the dopant-free HTM are potential candidates for large-scale production perovskite solar cell. Full article

Polymers from norbornenes are of interest for applications in opto- and microelectronic (low dielectric materials, photoresists, OLEDs). Norbornenes with ester motifs are among the most readily available norbornene derivatives. However, little is known about dielectric properties and the gas-transport of polynorbornenes from such monomers. Herein, we synthesized a new metathesis polymer from exo-5-norbornenecarboxylic acid and 1,1′-bi-2-naphthol. The designed monomer was obtained via a two-step procedure in a good yield. This norbornene derivative with a rigid and a bulky binaphthyl group was successfully polymerized over the 1st generation Grubbs catalyst, affording high-molecular-weight products (M_w ≤ 1.5·10⁶) in yields of 94–98%. The polymer is amorphous and glassy (T_g = 161 °C), and it shows good thermal stability. Unlike most, polyNBi is a classic low-permeable glassy polymer. The selectivity of polyNBi was higher than that of polyNB. Being less permeable than polyNB, polyNBi unexpectedly showed a lower value of dielectric permittivity (2.7 for polyNBi vs. 5.0 for polyNB). Therefore, the molecular design of polynorbornenes has great potential to obtain polymers with desired properties in a wide range of required characteristics. Further tuning of the gas separation efficiency can be achieved by attaching an appropriate substituent to the ester and aryl group. Full article

Hybrid polymer films of polyvinyl pyrrolidone (PVP)/polyvinyl alcohol (PVA) embedded with gradient levels of Bi-powder were prepared using a conventional solution casting process. XRD, FTIR, and SEM techniques have been used to examine the micro/molecular structure and morphology of the synthesized flexible films. The intensities of the diffraction peaks and transmission spectrum of the PVP/PVA gradually declined with the introduction of Bi-metal. In addition, filler changes the microstructure surface of the pure film. The modification in the microstructure leads to an enhancement in the optical absorption characteristic of the blend films. The indirect allowed transition energy was calculated via Tauc’s and ASF (Absorption Spectra Fitting) models. The decrease in the hybrid film’s bandgap returns to the localized states in the forbidden region, which led the present films to be suitable for photo-electric, solar cell, etc., applications. The relation between the transition energy and the refractive index was studied. The enhancement in the refractive index with Bi-metal concentrations led to use the as-prepared films in optical sensors. The rise of Bi-metal concentrations leads also to the improvement of the nonlinear susceptibility and refractive parameters. The optical limiting characteristics revealed that the higher concentration dopant films reduce the light transmission intensity which is appropriate for laser attenuation and optical limiting in photonic devices. The results suggest that hybrid films are promising materials in a wide range of opto-electronic applications. Full article

Bi_1-xMg_xFeO₃ (BMFO, x = 0, 0.02, 0.04, 0.06 and 0.08) multiferroic films were directly synthesized on flexible stainless steel (FSS), save the bottom electrode process, by means of sol–gel spin-coating technology. The effects of different bending conditions on ferroelectric, dielectric and leakage-current properties of BMFO films were investigated. The leakage-current densities of BiFeO₃ (BFO, x = 0) and BMFO (x = 0.06) films were 5.86 × 10⁻⁴ and 3.73 × 10⁻⁷ A/cm², which shows that the BMFO (x = 0.06) has more than three orders of magnitude lower than that of BFO film. The residual polarization (2 Pr) can be enhanced from 120 to 140 μC/cm². The proper doping of Mg in BiFeO₃ film could provide an effective method for reducing the leakage-current values as well as boosting the ferroelectric properties. In this study, the leakage-current mechanism of low electric field and high electric field of BMFO film is analyzed and established. In addition, the flexible BMFO film maintains practical ferroelectric and leakage-current properties at retention time of 10⁶ s under different symmetry bending conditions. These results indicate that the BFMO film will be very practical in opto-electronic and storage device applications. Full article

Canonical transient receptor potential (TRPC) channels were identified as key players in maladaptive remodeling, with nuclear factor of activated T-cells (NFAT) transcription factors serving as downstream targets of TRPC-triggered Ca²⁺ entry in these pathological processes. Strikingly, the reconstitution of TRPC-NFAT signaling by heterologous expression yielded controversial results. Specifically, nuclear translocation of NFAT1 was found barely responsive to recombinant TRPC3, presumably based on the requirement of certain spatiotemporal signaling features. Here, we report efficient control of NFAT1 nuclear translocation in human embryonic kidney 293 (HEK293) cells by light, using a new photochromic TRPC benzimidazole activator (OptoBI-1) and a TRPC3 mutant with modified activator sensitivity. NFAT1 nuclear translocation was measured along with an all-optical protocol to record local and global Ca²⁺ pattern generated during light-mediated activation/deactivation cycling of TRPC3. Our results unveil the ability of wild-type TRPC3 to produce constitutive NFAT nuclear translocation. Moreover, we demonstrate that TRPC3 mutant that lacks basal activity enables spatiotemporally precise control over NFAT1 activity by photopharmacology. Our results suggest tight linkage between TRPC3 activity and NFAT1 nuclear translocation based on global cellular Ca²⁺ signals. Full article

Metallic structures can be used for the localized heating of fluid and the controlled generation of microfluidic currents. Carefully designed currents can move and trap small particles and cells. Here we demonstrate a new bi-metallic substrate that allows much more powerful micro-scale manipulation. We show that there are multiple regimes of opto-fluidic manipulation that can be controlled by an external laser power. While the lowest power does not affect even small objects, medium power can be used for efficiently capturing and trapping particles and cells. Finally, the high-power regime can be used for 3D levitation that, for the first time, has been demonstrated in this paper. Additionally, we demonstrate opto-fluidic manipulation for an extraordinarily dynamic range of masses extending eight orders of magnitude: from 80 fg nano-wires to 5.4 µg live worms. Full article

The non-centrosymmetric bismuth-based oxyborate crystals have been extensively studied for non-linear optical, opto-electric and piezoelectric applications. In this work, single crystal growth and electro-elastic properties of α-BiB₃O₆ (α-BIBO) and Bi₂ZnB₂O₇ (BZBO) crystals are reported. Centimeter-sized α-BIBO and BZBO crystals were grown by using the Kyropoulos method. High resolution X-ray diffraction tests were performed to assess the crystal quality. The full-width at half-maximum values (FWHM) of the rocking curves were evaluated to be 35.35 arcsec and 47.85 arcsec for α-BIBO and BZBO samples, respectively. Moreover, the electro-elastic properties of α-BIBO and BZBO crystals are discussed and summarized, based on which the radial extensional and the face shear vibration modes were studied for potential acoustic device applications. The radial extensional mode electro-mechanical coupling factors k_p were evaluated and found to be 32.0% and 5.5% for α-BIBO and BZBO crystals, respectively. The optimal crystal cuts with face shear mode were designed and found to be (YZt)/−53° (or (YZt)/37° cut) for α-BIBO crystal, and (ZXt)/±45° cut for BZBO crystal, with the largest effective piezoelectric coefficients being in the order of 14.8 pC/N and 8.9 pC/N, respectively. Full article

The Electrochemical Atomic Layer Deposition (E-ALD) technique is used for the deposition of ultrathin films of bismuth (Bi) compounds. Exploiting the E-ALD, it was possible to obtain highly controlled nanostructured depositions as needed, for the application of these materials for novel electronics (topological insulators), thermoelectrics and opto-electronics applications. Electrochemical studies have been conducted to determine the Underpotential Deposition (UPD) of Bi on selenium (Se) to obtain the Bi₂Se₃ compound on the Ag (111) electrode. Verifying the composition with X-ray Photoelectron Spectroscopy (XPS) showed that, after the first monolayer, the deposition of Se stopped. Thicker deposits were synthesized exploiting a time-controlled deposition of massive Se. We then investigated the optimal conditions to deposit a single monolayer of metallic Bi directly on the Ag. Full article