Sorting and separation of microparticles by surface properties using liquid crystal-enabled electro-osmosis

Sorting and separation of microparticles is a challenging problem of interdisciplinary nature. Existing technologies can differentiate microparticles by their bulk properties, such as size, density, electric polarizability, etc. The next level of challenge is to separate particles that show identical bulk properties and differ only in subtle surface features, such as functionalization with ligands. In this work, we propose a technique to sort and separate particles and fluid droplets that differ in surface properties. As a dispersive medium, we use a nematic liquid crystal (LC) rather than an isotropic fluid, which allows us to amplify the difference in surface properties through distinct perturbations of LC order around the dispersed particles. The particles are placed in a LC cell with spatially distorted molecular orientation subject to an alternating current electric field. The gradients of the molecular orientation perform two functions. First, elastic interactions between these pre-imposed gradients and distortions around the particles separate the particles with different surface properties in space. Second, these pre-imposed patterns create electro-osmotic flows powered by the electric field that transport the sorted particles to different locations thus separating them. The demonstrated unique sorting and separation capability opens opportunities in lab-on-a-chip, cell sorting and bio-sensing applications

Sequential emitter identification method based on D-S evidence theory

This paper proposes a novel sequential identification method for enhancing the anti-jamming performance and for accurate recognition rate of the emitters’ individual identification in the complicated environment. The proposed method integrates the D-S evidence theory and features extraction that can get the utmost out of features of information systems and decrease the influence of uncertain factors in the signal processing. Firstly, selected features are extracted from intercepted signals. Then, the proposed self-adaptive fusing rule based on the decision vector is utilized to fuse the evidences that are transformed by features and the previous fusing information. Finally, recognition results can be obtained by judgment rules. The simulation analysis demonstrates that self-adaptive fusing rule can achieve a great balance between computational efficiency and accurate identifying rate. While comparing with other identifying methods, the proposed sequential identifying method can provide more accurate and stable recognition results, which makes the utmost care and use of existing information

Liquid Crystals with Patterned Molecular Orientation as an Electrolytic Active Medium

Transport of fluids and particles at the microscale is an important theme both in fundamental and applied science. One of the most successful approaches is to use an electric field, which requires the system to carry or induce electric charges. We describe a versatile approach to generate electrokinetic flows by using a liquid crystal (LC) with surface-patterned molecular orientation as an electrolyte. The surface patterning is produced by photo-alignment. In the presence of an electric field, the spatially varying orientation induces space charges that trigger flows of the LC. The active patterned LC electrolyte converts the electric energy into the LC flows and transport of embedded particles of any type (fluid, solid, gaseous) along a predesigned trajectory, posing no limitation on the electric nature (charge, polarizability) of these particles and interfaces. The patterned LC electrolyte exhibits a quadratic field dependence of the flow velocities; it induces persistent vortices of controllable rotation speed and direction that are quintessential for micro- and nanoscale mixing applications.Comment: 35 pages, 10 figure

Monolithic shape-programmable dielectric liquid crystal elastomer actuators

Macroscale robotic systems have demonstrated great capabilities of high speed, precise, and agile functions. However, the ability of soft robots to perform complex tasks, especially in centimeter and millimeter scale, remains limited due to the unavailability of fast, energy-efficient soft actuators that can programmably change shape. Here, we combine desirable characteristics from two distinct active materials: fast and efficient actuation from dielectric elastomers and facile shape programmability from liquid crystal elastomers into a single shape changing electrical actuator. Uniaxially aligned monoliths achieve strain rates over 120%/s with energy conversion efficiency of 20% while moving loads over 700 times the actuator weight. The combined actuator technology offers unprecedented opportunities towards miniaturization with precision, efficiency, and more degrees of freedom for applications in soft robotics and beyond

Plasmonic Metasurfaces with High UVâ Vis Transmittance for Photopatterning of Designer Molecular Orientations

Recent developments of utilizing plasmonic metasurfaces in photopatterning of designer molecular orientations have facilitated numerous new applications of liquid crystals; while the optical efficiency of the metamasks remains a critical issue, especially in the UV region. Here a new design of plasmonic metasurfaces made of parallelepiped arrays is presented which yield very high and broadband transmission in the UVâ vis wavelength range. It is shown that this plasmonic metamask exhibits two polarization peaks originated from a cavity mode and lattice resonance respectively and demonstrated that complex designer molecular orientations can be photopatterned by using this metamask with significantly reduced exposure time. This type of highâ efficiency broadband plasmonic metasurfaces is not only important for high resolution photopatterning of molecular orientation but also tailorable for various other flat optics applications in the UV and near UV regions.Spatially variant molecular orientations are central to many liquid crystal applications. Here a new design of plasmonic metasurfaces with ultrahigh optical transmissions as metamasks for photopatterning arbitrary designer molecular orientations is presented and it is demonstrated that such metamasks can significantly reduce the exposure time of the photopatterning.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149547/1/adom201900117-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149547/2/adom201900117.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149547/3/adom201900117_am.pd

An Organic–Inorganic Hybrid Cathode Based on S–Se Dynamic Covalent Bonds

A diphenyl trisulfide–selenium nanowire (DPTS‐Se) organic–inorganic hybrid cathode material is presented for rechargeable lithium batteries. During discharge, three voltage plateaus associated with three lithiation processes are observed. During recharge, the combination of the radicals formed upon delithiation leads to several new phenyl sulfoselenide compounds which are confirmed by HPLC‐QTof‐MS. The hybrid cathode exhibits superior cycling stability over pristine Se or DPTS as cathode alone. The first discharge shows a capacity of 96.5 % of the theoretical specific capacity and the cell retains 69.2 % of the initial capacity over 250 cycles. The hybrid cathode also shows a high Coulombic efficiency of over 99 % after 250 cycles. This study demonstrates that the combination of organic polysulfide and selenium can not only improve the utilization of active materials but also enhance the cycling performance

Possible interpretation of the ZbZ_b(10610) and ZbZ_b(10650) in a chiral quark model

Motivated by the two charged bottomonium-like resonances $Z_b$(10610) and $Z_b$(10650) newly observed by the Belle collaboration, the possible molecular states composed of a pair of heavy mesons, $B\bar{B}, B\bar{B}^*, B^*\bar{B}^*, B_s\bar{B}$, etc (in S-wave), are investigated in the framework of chiral quark models by the Gaussian expansion method. The bound states $B\bar{B}^*$ and $B^*\bar{B}^*$ with quantum numbers $I(J^{PC})=1(1^{+-})$, which are good candidates for the $Z_b(10610)$ and $Z_b(10650)$ respectively, are obtained. Other three bound states $B\bar{B}^*$ with $I(J^{PC})=0(1^{++})$, $B^*\bar{B}^*$ with $I(J^{PC})=1(0^{++}), 0(2^{++})$ are predicted. These states may be observed in open-bottom or hidden-bottom decay channel of highly excited $\Upsilon$. When extending directly the quark model to the hidden color channel of the multi-quark system, more deeply bound states are found. Future experimental search of those states will cast doubt on the validity of applying the chiral constituent quark model to the hidden color channel directly.Comment: 13 pages, 1 figure, title and some arguments in the abstract and section 5 are revised, results unchange

Liquid crystal elastomer coatings with programmed response of surface profile

Stimuli-responsive liquid crystal elastomers (LCEs) with a strong coupling of orientational molecular order and rubber-like elasticity, show a great potential as working elements in soft robotics, sensing, transport and propulsion systems. We demonstrate a dynamic thermal control of the surface topography of LCE coatings achieved through pre-designed patterns of in-plane molecular orientation. These patterns determine whether the LCE coating develops elevations, depressions, or in-plane deformations. The deterministic dependence of the out-of-plane dynamic surface profile on the in-plane orientational pattern is explained by activation forces. These forces are caused by two factors: (i) stretching-contraction of the polymer networks driven by temperature; (ii) spatially varying orientation of the LCE. The activation force concept brings the responsive LCEs into the domain of active matter. The demonstrated relationship can be used to design programmable coatings with functionalities that mimic biological tissues such as skin

Preclinical and clinical evidence for the treatment of non-alcoholic fatty liver disease with soybean: A systematic review and meta-analysis

Non-alcoholic fatty liver disease (NAFLD), a prevalent public health issue, involves the accumulation of triglycerides in hepatocytes, which is generally considered to be an early lesion of liver fibrosis and cirrhosis. Thus, the development of treatments for NAFLD is urgently needed. This study explored the preclinical and clinical evidence of soybeans to alleviate NAFLD. Studies indexed in three relevant databases—Web of Science, PubMed, and Embase—between January 2002 and August 2022 were retrieved. A total of 13 preclinical studies and five RCTs that included 212 animals and 260 patients were included in the present analysis. The preclinical analysis showed that liver function indices (AST, SMD = −1.41, p < 0.0001 and ALT, SMD = −1.47, p < 0.0001) were significantly improved in the soybean group compared to the model group, and fatty liver indicators (TG, SMD = −0.78, p < 0.0001; TC, SMD = −1.38, p < 0.0001) and that oxidative stress indices (MDA, SMD = −1.09, p < 0.0001; SOD, SMD = 1.74, p = 0.022) were improved in the soybean group. However, the five RCTs were not entirely consistent with the preclinical results; however, the results confirmed the protective effect on the liver. The results of the clinical RCTs showed that soybean significantly affected liver function, fatty liver, and oxidative stress indicators (ALT, SMD = −0.42, p = 0.006; TG, SMD = −0.31, p = 0.039; MDA, SMD = −0.76, p = 0.007). The current meta-analysis combined preclinical and clinical studies and verified that soybean could protect the liver in NAFLD by regulating lipid metabolism and oxidative stress factors via the Akt/AMPK/PPARα signaling pathway. Soybean might be a promising therapeutic agent for treating non-alcoholic fatty liver disease.Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/#myprospero), identifier (CRD42022335822)