Cell Reports Physical Science最新文献

Photo-responsive hydrogel systems have attracted significant attention for their controllability, intelligent responsiveness, and reversibility. This study delves into the effect of tunable space-confined networks on anion transport in photo-responsive hydrogels. Employing azobenzene (Azo) and β-cyclodextrin (β-CD), the hydrogel was loaded into anodic aluminum oxide (AAO) to form the AAO-hydrogel membrane. Sodium dodecyl sulfonate (SDS) is chosen to investigate mass transmembrane transport. In low-degree space-confined aluminum oxide-hydrogel membrane (LSAHM), a looser structure was formed due to the breakup of the connection between Azo and β-CD with ultraviolet (UV)-light irradiation. With visible-light (vis-light) irradiation, the SDS is replaced with trans-Azo due to the more stable trans-Azo@β-CD complex, resulting in narrow channels. For high-degree space-confined AHM (HSAHM), the interaction between SDS and β-CD could be omitted due to space confinement. Also, controllable SDS-assisted cationic peptide transport is achieved with HSAHM. This work provides a comprehensive analysis of hydrogel structure variations, offering nuanced approaches to hydrogel design.

The goal of artificial neural networks is to utilize the functions of biological brains to develop computational algorithms. However, these purely artificial implementations cannot achieve the adaptive behavior found in biological neural networks (BNNs) via their inherent memory. Alternative computing mediums that integrate biological neurons with computer hardware have shown similar emergent behavior via memory, as found in BNNs. By applying current theories in BNNs, can emergent memory functions be achieved with alternative mediums? Electro-active polymer (EAP) hydrogels were embedded in the simulated game-world of Pong via custom multi-electrode arrays and feedback between motor commands and stimulation. Through performance analysis within the game environment, emergent memory acquisition was demonstrated, driven by ion migration through the hydrogels.

Dye-sensitized solar cells (DSSCs) have garnered significant research attention for their cost-effectiveness, transparency, flexibility, etc. In this work, a copper complex of a bipyridine-modified mediator, [Cu(dmodmbp)₂]^+/2+, is developed to minimize the loss in fill factor (FF). A DA2 dye, inspired by the structures of previously reported LC4 and LC5 dyes, incorporates cascade acceptors to enhance light absorption and increase the short-circuit current (J_SC). These innovations lead to highly efficient DSSCs with an impressive power conversion efficiency (PCE) of 10.2% (J_SC = 12.10 mA cm⁻², open-circuit voltage [V_OC] = 1.11 V, FF = 0.764) as well as a remarkable photostability. A test over 95 days shows that 88% of the initial PCE can be maintained, with V_OC, J_SC, and FF retaining 98%, 97%, and 93% of their initial values, respectively.

With the growing need for lithium-ion batteries in high-power applications, an accurate estimation of battery state of health is critical for long cyclability. In this work, an analytics approach based on pulse voltammetry is presented for lithium-ion batteries. A physics-based modeling framework is developed to predict pulse voltammogram signatures for generic voltage pulses. In combination with a parameter estimation technique, this model presents an in situ diagnostic tool that captures key electrode-specific parameters with rapid accuracy. Using this approach, we quantify degradation descriptors such as the growth of the resistive layer, interfacial area evolution, and lithium-intercalation state. Pulse voltammetry signatures, obtained periodically during fast-charge cycling experiments, show distinct trends at low temperature and room temperature. Active particle cracking plays a major role in the low-temperature capacity fade of lithium-ion cells, while a combination of cracking and impedance rise is the major cause of degradation at room temperature.

The chemical state of nickel anodes during the oxygen evolution reaction can impact their electrocatalytic performance. Here, X-ray photoelectron and absorption spectroscopies reveal the chemical state of nickel nanoparticles under oxygen evolution reaction conditions in a mildly alkaline carbonate-bicarbonate buffer solution. Ni²⁺ and Ni³⁺ species are observed at the reaction onset potential with a 7:4 ratio, with no remaining metallic nickel. These species include NiO, which increasingly converts to other Ni²⁺ and Ni³⁺ species once the potential is increased above the onset potential. Conversely, when a 20-nm-thick nickel film is used instead of nickel nanoparticles, a significant amount of metallic nickel remains in the inner layers. Nickel nanoparticles also undergo significant morphological and structural changes during the reaction, as evidenced by ex situ transmission electron microscopy. Amorphization of the nanoparticles is attributed to significant H₂O incorporation, with the oxygen intensity increasing both in operando and ex situ measurements.

Intensity-based fluorescence imaging suffers from spectral overlap and optical background interference. As an alternative, fluorescence lifetime measurements on the nanosecond level are also largely constrained. Herein, we propose phase-sensitive detection of photoswitchable probes containing naphthopyran and fluorescent donors. The method features reaction kinetics in the millisecond-to-second regime, allowing frequency domain detection with cost-effective equipment. A phase shift (Δϕ) in the fluorescence of the probes is extracted by fast Fourier transform, establishing a dependence on the molar ratio of donor to acceptor. Thus, Δϕ is proposed as a self-referencing quantity for selective highlighting of fluorescent probes and a dynamic signal readout in chemical sensing. Phase-sensitive detection of protamine, a polycationic protein often used as a neutralizer of the anticoagulant heparin during surgery, is successfully realized based on the platform.

Battery operating data from real-life scenarios are riddled with randomness, complexity, and multi-cell grouping, posing significant challenges for applying lifetime prognostic approaches developed from laboratory scenarios. To address this, we have conducted extensive experimental investigations into battery degradation across laboratory and real-life scenarios spanning a 4 year period, involving a total of approximately 546,000 charge-discharge cycles across hundreds of cells and packs. In addition to our experimental investigations, we develop a lifetime prognosis approach by creatively incorporating the concept of cumulative utilization lifetime. Our approach highlights the significant potential of transferring knowledge gained from standardized laboratory scenarios to diverse real-world conditions. It consistently improves performance from early prediction to real-time prediction, achieving a remarkable error margin of around 5% and millisecond-level computational efficiency on a portable laptop with no dedicated graphics. Furthermore, our experimental investigations underscore the beneficial effects of seasonal low temperatures on prolonging battery lifetime.

Cholesteric liquid crystals (CLCs) exhibit optical properties that are highly responsive to temperature or electric fields. Here, we report an approach to aiding in photosensitive epilepsy treatment by developing a thermal-controlled CLC wavelength filter lens. This lens demonstrates exceptional optical tunability, enabling it to dynamically change its stopband in response to temperature changes. At room temperature, the stopband of the CLC lens is outside the visible spectrum, rendering the lens functionally similar to normal glass. As the temperature rises to 36.5°C, the lens efficiently blocks light within the 660- to 720-nm wavelength range, which is the known trigger wavelength for photosensitive epilepsy. CLC materials with opposite handedness are used to achieve over 98% light cutoff at the stopband. We propose a control system for dynamically controlling the temperature in real time. The tunable lenses offer a solution for mitigating the effects of specific light stimuli on affected individuals.