In this study, based on the collection process, three-dimensional aligned fiber scaffolds from gelatin and zein protein were manufactured using Forcespinning®. The homogeneous blending of gelatin:zein (1:4) showed improved tensile and good hydrophobic properties (water contact angle of 115 °C). Cell viability, adhesion, proliferation, and drug release were measured. The cell viability was studied with human fibroblasts and a low cytotoxic effect was observed. Berberine drug release was measured and sustained release rate was observed over 15 days. The morphologic features, prolonged drug release, and cytotoxicity results suggest that these fibers could be appropriate for drug delivery and tissue engineering applications.

A longitudinal field component parallel to the wave vector is generally considered in nonlocal optical response. Longitudinal volume plasmons accompanied by inhomogeneous internal field optically break symmetry for isotropic metal nanoparticles. Here, natural circular dichroism in the interband transitions of TiN nanocubes, Au nanospheres, and Cu nanospheres in solution is presented. A field gradient or volume plasmons exert an electric force and consequently Lorentz force on bound valence-band electrons inside the nanoparticles. It is generalized that interband transitions in nanoparticles intrinsically produce a positive rotational strength and optical right-handedness. Electromechanical chiralty is introduced to explain the optical activity of achiral nanoparticles.

We present for the first time the feasibility to recover the stiffness (here shear modulus) distribution of a three-dimensional heterogeneous sample using measured surface displacements and inverse algorithms without making any assumptions about local homogeneities and the stiffness distribution. We simulate experiments to create measured displacements and augment them with noise, significantly higher than anticipated measurement noise. We also test two-dimensional problems in plane strain with multiple stiff inclusions. Our inverse strategy recovers the shear modulus values in the inclusions and background well, and reveals the shape of the inclusion clearly.

This work presents an in-depth study of how the choice of boundary conditions can impact upon the calculated photovoltage and photocurrent in photoelectrochemical (PEC) devices. Utilizing a floating boundary condition for the electrostatic potential and pseudo-Schottky boundary conditions for the interfacial electron/hole currents, we show simultaneous calculation of photovoltage and photocurrent. We also explore the significance of capturing the photovoltage, with proper boundary conditions, to accurately replicate practical photocurrent along with the realistic band alignments. Finally, our results decouple the interfacial hole transfer from the recombination at the interface/space-charged region and suggest possible methods to engineer the mesoscopic transfer process at PEC electrodes.

In this study, a novel shape memory polymer (SMP), eggshell membrane (ESM), with macroscopic mesh structures and microscopic crosslinked protein fibers, has shown water-stimulated shape recovery characteristics. Our results show that the collagen triple-helical molecular chains and disulfide-rich motifs in the ESM function as net-points retaining essential structures during deformation, while hydrogen bonds play a key role as switch units for shape recovery through water stimulation. We also demonstrate that programmable shape recovery characteristics of ESM can be obtained by modulating the number of net-points. This study may inspire the design of new programmable SMPs.

End-stage renal disease (ESRD) is a life-threatening illness that presents significant healthcare challenges. About 90% of ESRD patients receive hemodialysis treatment, but the currently available hemodialysis systems are bulky and prone to complications. We report the design of a microfluidic hemodialysis device composed of two polydimethylsiloxane (PDMS) chambers separated by a cellulose ester (CE) membrane. The polyethylene glycol-passivated PDMS and CE surfaces reduced platelet adhesion by 74% and 86%, respectively. Moreover, the device exhibited a higher urea clearance rate per unit area than a healthy kidney. The reported design sets the foundation for a next-generation biomimetic portable hemodialysis device.

The electrochemical catalytic effects of the NiO islands and layer on n-type GaN were investigated. The NiO islands covered some parts of the GaN surface and were seen to improve photoanodic current and prevent photoanodic corrosion. However, the NiO layer was found to worsen the photoanodic current. Hole transportation is thought to occur from the GaN valence band edge to the NiO valence band edge in their surface plane direction due to the band alignment. In addition, the electron capture for water oxidation is expected to be the valence band edge of the NiO instead of the intermediate state.

Biosilica from living diatom microalgae has recently attracted the interest of the scientific community and found several applications in bio-nanotechnology. Among silica-maker organisms, diatom microalgae represent the most attractive marine microorganisms, featuring highly hierarchical, nanotextured and porous silica walls. These biologic structures, known as “frustules” are also chemically addressable via simple chemical synthesis. In this work, we propose new diatom-based hybrid materials consisting of biosilica extracted from living Thalassiosira weissflogii coated with polydopamine (PDA) films. The adhesion properties of the PDA were exploited to decorate the silica surface with silver nanoparticles. These multifunctional heterostructures can be useful for applications ranging from bioelectronics to biomedicine.

Photovoltaic organic semiconductors are emerging in many therapeutic applications, including drug delivery and optical control of cell function. However, for their safe use the possible concomitant elicitation of undesired responses in target cells need to be carefully evaluated. Here we describe molecular responses activated by semiconducting polymer nanoparticles based on poly(3-hexyl)thiophene (P3HT) in the model Hydra vulgaris, previously shown to respond to P3HT-NP photostimulation and showed a decrease in the total antioxidant capacity and an increase in the DNA and protein oxidation levels, paving the way to a novel use of photovoltaic devices to control intracellular redox equilibrium.

Geometrical features are known to be very important in neuronal growth and the formation of neuronal networks. We present an experimental and theoretical investigation of axonal growth and dynamics for neurons cultured on patterned polydimethylsiloxane surfaces. We utilize fluorescence microscopy to image the axonal dynamics and show that these substrates impart a strong directional bias to neuronal growth. We model axonal dynamics using a general stochastic model and use this framework to extract key dynamical parameters. These results provide novel insight into how geometrical cues influence neuronal growth and represent important advances toward bioengineering neuronal growth platforms.

Biologic neural networks are immersed in common electrolyte environment, and homeoplasticity or global factors of this environment are forcing specific normalization functions that regulate the overall network behavior. In this work, a common electrolyte is used to gate a grid of organic electrochemical devices. The electrolyte functions as a global parameter that controls collectively the device grid. Statistical analysis of the grid and the subsequent definition of global metrics reveal that the grid behaves similarly to a single device. This global control modulates the gain of the device grid, a phenomenon analog to multiplicative scaling in biologic networks. This work demonstrates the potential use of electrolytes as homeostatic media in neuromorphic device architectures.

We present a first-principles investigation on the optical absorption of tungsten trioxide, an electrochromic material. Using state-of-the-art techniques, the absorption spectra are calculated for the cubic, monoclinic, and amorphous phases. For both crystalline and disordered structures, doping induces strong absorption in the infrared. Absorption in the visible range increases with the degree of structural distortion; the absorption coefficient in the blue exceeds 103 cm−1 at doping levels above 1020 cm−3 in the monoclinic phase. Increased disorder in disordered structures significantly enhances the visible-range absorption. We identify the microscopic mechanism as optical absorption originating at conduction-band-derived states that are filled by doping.

Herein, we show that scanning probe microscopy (SPM) is an effective tool permitting to disclose the nature of the colossal dielectric permittivity characteristic of CaCu3Ti4O12 (CCTO) compound. SPM data confirm the existence of micro- and nanoscale barrier layer capacitance mechanisms which simultaneously contribute to the electrical conductivity of the material. The former mechanism is associated with the potential grain-to-grain barriers. The latter mechanism involves the barriers created by intragrain structural defects. The results of the SPM study shed new light on the origin of the colossal dielectric constant in CCTO.

Ag deposition-based multicolor electrochromic (EC) device we reported can switch various optical states among transparent, black, silver, cyan, magenta, and yellow by only using electrochemical deposition of Ag. However, the EC device had poor color retention property under open-circuit state because of dissolution of deposited Ag metal by Cu2+ ions, which is essential because it acts as redox material at counter electrode. Here, we introduced an anion exchange membrane to separate Cu2+ from the Ag deposit. The improved device achieved longer retention time of colored state. It is effective to maintain the coloring state without electric power for practical application.

In this work, we present a solvothermal method to prepare bismuth (Bi)-doped CuGaS2 chalcopyrite nanocrystals ink and apply it to an all-solution-processed approach for the preparation of films with a thickness of approximately 730 nm and with enhanced optical properties and lower band gap energy than the undoped semiconductor films. The low-cost deposition method is comprised by spray deposition of the chalcogenide nanocrystals ink onto the molybdenum substrates, producing microcrystalline films with grains larger than 400 nm originated from coalescence of Bi-doped nanocrystals. Bi-doped CuGaS2 microcrystalline films are a good candidate to be applied as an absorber layer in thin-film solar cells.

Biofilms can damage implants and are difficult to treat. Here, we assessed the performance of a tripeptide that self-assembles into an antifouling coating over a broad range of shear conditions that are relevant to biomedical applications. Adhesion assays were performed using a parallel plate flow chamber. The results show that the coating can reduce Escherichia coli adhesion up to 70% when compared with glass. At a shear rate of 15/s, typical for urinary catheters, the coating reduced the adhesion by more than 50%. These findings suggest critical features that should be considered when developing surfaces for biomedical purposes.

There is an increasing interest in the generation of well-defined nanoparticles (NPs) not only because of their size-related particular properties, but also because they are promising building blocks for more complex materials in nanotechnology.

Here, we will shortly introduce the gas-phase synthesis technology that has evolved rapidly in the last years and allows the fabrication of complex NPs with controllable and tuneable chemical composition and structure while keeping very good control over the size distribution. We will also address some limitations of the technology (stability over time, production yield, etc.) and discuss possible solutions.

The emerging planar subwavelength microlens has attracted wide attention recently. There exists a trade-off in the selection of phase shifter materials for the lens designed with linearly polarized incidence. In this work, we have discovered that it is possible to utilize tapered nanostructure to increase the transmission of phase shifters built with high refractive index materials. A typical grating microlens is demonstrated to examine the effectiveness of taper-enhancement effect—the focus efficiency is increased from 9% to 28% with the properly designed tapered sidewall. Our work will provide a novel method to enhance performance using high refractive index materials in the emerging microlens field.