Constant Charge Density Research Articles

Manufacturing strategies for highly sensitive and self-powered piezoelectric and triboelectric tactile sensors

Abstract Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications. The working principles of piezoelectric and triboelectric nanogenerators provide strategies for enhancing output voltage signals to achieve high sensitivity. Increasing the piezoelectric constant and surface triboelectric charge density are key factors in this enhancement. Methods such as annealing processes, doping techniques, grain orientation controls, crystallinity controls, and composite structures can effectively enhance the piezoelectric constant. For increasing triboelectric output, surface plasma treatment, charge injection, microstructuring, control of dielectric constant, and structural modification are effective methods. The fabrication methods present significant opportunities in tactile sensor applications. This review article summarizes the overall piezoelectric and triboelectric fabrication processes from materials to device aspects. It highlights applications in pressure, touch, bending, texture, distance, and material recognition sensors. The conclusion section addresses challenges and research opportunities, such as limited flexibility, stretchability, decoupling from multi-stimuli, multifunctional sensors, and data processing.

Magnetization without spin: Effective Lagrangian of itinerant electrons

In this paper, an effective Lagrangian of an itinerant electron system of finite density at a finite magnetic field is obtained. It includes a Chern-Simons term of electromagnetic potentials of lower-scale dimensions compared to those studied before. This term has an origin in the many-body wave function and a unique topological property that is independent of a spin degree of freedom. The coupling strength is proportional to ρeB, which is singular at B=0 for a constant charge density. The effective Lagrangian at a finite B represents the physical effects at B≠0 properly. A universal shift of the magnetic field known as the Slater-Pauling curve is obtained from the effective Lagrangian.

Modulation of electrical properties of sputtered Ta2O5 films by variation of RF power and substrate temperature

Dielectric thin films are important building blocks of microelectronic devices, and hence, research on the development of high-k dielectric thin films has drawn tremendous research interest. In this research, thin films of tantalum oxide (Ta2O5), a high-k dielectric material, are deposited on the Si substrate by the radio frequency (RF) magnetron sputtering technique. During the deposition of Ta2O5 thin film, the sputtering parameters such as sputtering power and substrate temperature were systematically varied, and post-deposition structural, morphological, and electrical properties of sputtered Ta2O5 films are studied by x-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscope, capacitance–voltage (C-V) and current–voltage (I-V) measurement techniques. The annealed Ta2O5 thin film at the temperature of 900 °C for 1 h possesses polycrystalline nature with β—phase orthorhombic crystal structure. The film deposited at 150 W and substrate temperature at room temperature has shown comparatively lower surface roughness, which depicts the energy, and mobility of adatoms greatly influenced by RF power and substrate temperature. With the increase in sputtering power, the oxide charge density (Qox) is found to increase. On the other hand, Qox is found to decrease with the increase in substrate temperature. The film deposited at RF power of 150 W and substrate temperature of 300 °C is found to be of high dielectric constant, low oxide and interface charge density, and lower leakage current.

A numerical study supplemented with theoretical analysis on streaming potential in a soft nanochannel influenced by ion partitioning and mobile surface charge-dependent wall slip

We consider the pressure-driven flow of an electrolyte in a soft channel with a hydrophobic charged surface coated with a diffuse polyelectrolyte layer (PEL) with constant volumetric charge density. The objectives are to enhance the streaming potential and electrochemical energy conversion efficiency in the modulated soft channel as well as to examine the influence of surface charge mobility-dependent slip velocity on the electrokinetics. The laterally mobile adsorbed surface charge modifies the slip velocity condition, which is coupled with the induced streaming potential. The ion partitioning effect arises due to the step change in dielectric constant between the PEL and the electrolyte that modifies the distribution of ions, which is incorporated through the Born energy difference of ions. The nonlinear coupled set of equations governing the electrokinetics in a soft channel is solved numerically through a control volume approach. A simplified model based on the Debye–Hückel approximation under certain limiting conditions is also derived, which compares well with the present numerical model for a lower range of charge density and non-overlapping Debye layers. We find that a modulation of a nanochannel by coating a PEL of lower dielectric constant on hydrophobic charged walls can significantly enhance the streaming current and energy conversion efficiency. In contrast with existing studies, we find that the mobile surface charge can have a positive impact on the electrochemical energy conversion efficiency in a soft nanochannel. The mobility of the surface charge attenuates the streaming current in a PEL-free channel and can enhance the streaming current for a suitable choice of PEL volumetric charge density.

Design and Performance Assessment of Split Gate Dielectric Modulated Junction less TFET Variation of Hfo2 by the Divided Gate Insulator for High Sensitivity Using Tcad Simulation

A number of more recent discoveries in microbiology have made reliable identification of nano-biomolecules and extensive analyses of them necessary. A variety of proteins, including DNA, biotin-streptavidin, amino acids, as well as many types of bacteria and viruses, must be found and analyzed in order to fully comprehend any odd behavior occurring inside of live cells. Rapid testing and detection are essential steps in preventing undiscovered biohazards from eradicating the human race and other terrestrial living things. Since many decades ago, developing an accurate, affordable biosensor has been a struggle for scientists [1]. When compared to pricey laboratory-based sensors and detection methods, FET-based lab-on-chip nano biosensors appear to be a promising substitute. It is significantly more dependable than conventional bulk sensors because of its size, affordability, low power consumption, resilience, faster response time, and better sensitivity [1]. Due to their precision, adaptability, and compatibility with embedded systems, dielectrically modulated FET biosensors with Nano cavities are emerging as a promising research area that can yield useful data on bio-analyses. As an alternative to conventionally doped TFET devices, using a charge plasma SiGe-heterojunction double gate TFET, a label-free biosensor can be produced, bypassing the need for conventional semiconductors, which require a large thermal budget and are susceptible to random dopant fluctuations (RDFs). The effect of changing the dielectric constant (k), the positive and negative charge density, the gate work function, and the cavity size has been investigated to better understand how these factors affect the performance of the proposed biosensor. These parameters modify the biosensor's electric characteristics, improving detection [2]. There is also discussion of how these factors influence the device's drain current, electric field, surface potential, sub-threshold swing (SS), insulator-to-metal film (ION/IOFF) ratio, and electron tunneling rate (ETR). The sensitivity of the drain current in the proposed biosensor is also investigated. There is no restriction on whether or whether the proposed structure is used for charged or neutral molecules.Under lower supply voltages, it is discovered that the SG-DM current JLFET's sensitivity is high, measuring 1.2 *10^3, with a potential sensitivity of 1.4 V. A result, the SG-DM [2] JLFET exhibits good application potential while consuming little power and having ahigh sensitivity.

Insight into Hofmeister effects on aggregation of 2:1 and 1:1 type clay minerals

Abstract2:1 and 1:1 types of clay minerals are ubiquitous in soil, and their different surface properties result in distinct environmental behaviours. In this study, dynamic light scattering (DLS) technology was adopted to determine the aggregation kinetics of 2:1 type (Montmorillonite [Mt]) and 1:1 type (Kaolinite [Ka]) clay minerals in different electrolytes. Hofmeister effects on their aggregation characteristics and mechanisms were explored. The results showed that the activation energy and critical coagulation concentration (CCC) for Mt and Ka aggregation followed Hofmeister sequences of Na+ > K+ > Cs+, Mg2+ > Ca2+ > Zn2+ ≈ Cd2+ > Cu2+> Pb2+. The analyses of physical insights into those differences revealed that the observed Hofmeister sequence was produced from the different non‐classical polarisation of cations and surface O atoms in the strong electric field of clay, which led to non‐electrostatic force adsorption of cations at the surface (or in the Stern layer). In this study, the effective charge coefficient γ was employed to characterise the intensity of the non‐electrostatic adsorption forces of cations arising from the non‐classical polarisation, and the γ values followed Na+ < K+ < Cs+, Mg2+ < Ca2+ < Zn2+ = Cd2+ < Cu2+ < Pb2+. For alkali and alkali earth metal cations with same valence, the more the electron layers, the ‘softer’ the electron cloud, the stronger the non‐classical polarisation effects in the electric field and the stronger ability to shield the electric field around the particle, which finally lead to the larger γ and lower CCC for clay minerals aggregation. For heavy metal cations, different s/p/d empty orbitals provided the basis for the difference in polarisation‐induced coordination between heavy metal cations with surface O atoms on clay. The results also showed that, the Hofmeister effects on Mt/Ka aggregation were different, it was from the differences in Hamaker constant and surface charge density for the two clay minerals.Highlights Mt and Ka aggregations exhibited different Hofmeister effects. Repulsive force among Mt particles was much larger than Ka. Cationic polarisation played critical role in particle interactions of Mt. Polarisation‐induced covalent adsorption of cations was observed at Mt surface.

Influence of fixed charge concentration and water uptake on ion sorption in AMPS/PEGDA membranes

Water content and charge density strongly influence ion sorption in charged membranes. However, isolating the individual effect of each parameter on ion sorption can be difficult due to experimental challenges associated with independently controlling these two variables during membrane synthesis. This frustrates development and validation of fundamental models and structure/property relationships. In this study, three series of uncharged and negatively charged hydrogel membranes were prepared using poly(ethylene glycol) diacrylate (PEGDA) as a cross-linker and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as an ionic monomer. Water content and charge density were controlled by varying AMPS content and PEGDA chain length. Ion sorption in these materials was measured using aqueous NaCl solutions at concentrations ranging from 0.01 to 1.0 M. At constant charge density, salt sorption increased as water content increased. At fixed water content, salt sorption decreased as charge density increased. Salt sorption in membranes with the highest water content and charge density was predicted using the Donnan/Manning model, which accounts for solution and membrane phase thermodynamic non-idealities. However, this approach could not predict sorption in weakly charged and uncharged membranes, presumably due to additional membrane phase thermodynamic non-idealities associated with ion solvation and uncharged polymer segments. • High ion activity coefficients in uncharged membranes suggest ions have a much greater affinity for aqueous solution than swollen, uncharged membranes. • The Donnan/Manning model predicts experimental sorption well for highly hydrated and/or highly charged membranes. • Model predictions agree poorly with experimental data for membranes that are less hydrated, weakly charged, or uncharged due to phenomena not accounted for in Manning's theory (e.g., dielectric exclusion and non-idealities introduced by polymer segment-water-ion interactions).

Energy Optimization of a Mirror‐Symmetric Spherical Triboelectric Nanogenerator

AbstractA general theoretical analysis of a 3D generic TENG structure is presented. Using a dimensionless formulation, it is demonstrated that the optimal TENG geometry does not depend on the frequency of the moving dielectric but the external ohmic impedance for maximum power output is inversely proportional to the frequency. It is also found that the energy is proportional to the cube of the size of the TENG, the square of the triboelectric charge density σT, and the angular frequency ω of the moving dielectric. In the case of a spherical TENG where the moving dielectric is a sphere and the electrodes are spherical caps on a larger sphere three dimensionless parameters that determine the harvested energy are identified: the ratio between the radii of the two spheres = r/R, the polar angle θ of the two spherical caps formed by the electrodes, and = ZεRω, whereZis the external impedance,Ris the radius of the large sphere, ε is the permittivity of the system, and ω is the angular frequency of the moving sphere. Under the crude assumption of constant charge density on the electrodes, the optimal parameters can be easily calculated. It is found that θ = 1.1 rad, = 0.67, and = 0.18.

Adsorption of Binary Mixture of Highly Positively Charged PTMA5M and Partially Negatively Charged PAA onto PSL Particles Studied by Means of Brownian Motion Particle Tracking and Electrophoresis

Effects of ionic strength on the adsorption of highly charged polycationic ((2-dimethylamino)ethyl methacrylate) methyl chloride quaternary salt (PTMA5M) individually as well as in a binary mixture with polyanionic acrylic acid (PAA) onto polystyrene sulfate latex (PSL) particles with negative charges were investigated by means of Brownian movement particle tracking and measurement of electrophoretic mobility. In addition, the adsorption mechanism was confirmed by Fourier transform infrared (FT-IR) and energy-dispersive X-ray (EDX) spectroscopic methods. The hydrodynamic thickness of the adsorbed polyelectrolyte layer (δH) and electrophoretic mobility (EPM) of particles as a function of concentration ratios of the two polyelectrolytes were measured to clarify the effect of negatively charged molecules on the structure of the positively charged adsorbed layer at various ionic strengths. Extremely thick δH was confirmed for the case of excess dosage of polycations. The δH decreased more significantly with the addition of PAA than increasing ionic strength. Interestingly, in the presence of PAA, the adsorbed layer thickness increased more at lower ionic strength than at higher ionic strength. In addition, the initial δH decreases remarkably after a time lapse of 1 h. Contrary to the decrease of the δH, almost all EPM either remained unchanged or increased over time depending on the concentration ratio of the two polyelectrolytes. Constant charge density, desorption of polyanions, and then reconformation of the adsorbed polycationic layer are proposed model components.

Electrically doped SiGe-heterojunction TFET based biosensor considering non-ideal hybridization issues: a simulation study.

Calibrated simulations are used to study a dielectric modulated, electrically doped, dual metal gate, SiGe heterojunction, double gate TFET biosensor in this work. Use of lower bandgap SiGe at the source side helps in improving the ON current of the biosensor. Electric doping is preferred over physical doping to overcome the random dopant fluctuations and high thermal budget problems. Non-ideal situations having partially and non-uniformly filled cavity regions are analyzed in this work. Partially filled cavity has fill factor less than 100% and is studied by considering 50%, 20%, and 10% fill factors. Different positions of biomolecules inside a partially filled cavity are also studied through extensive simulations and are found to affect the sensitivity largely. Four different non-uniform profiles, decreasing, increasing, convex and concave, are created in the cavity region and their sensitivity values are compared for different dielectric constants (k) and charge densities (Q_{mathrm{Bio}}). Among the different non-uniform profiles considered, maximum sensitivity is obtained for decreasing profile and it improves with an increase in dielectric constant and positive charge density while it decreases when negative charge density increases.

The Kerr-Schild double copy in Lifshitz spacetime

The Kerr-Schild double copy is a map between exact solutions of general relativity and Maxwell’s theory, where the nonlinear nature of general relativity is circumvented by considering solutions in the Kerr-Schild form. In this paper, we give a general formulation, where no simplifying assumption about the background metric is made, and show that the gauge theory source is affected by a curvature term that characterizes the deviation of the background spacetime from a constant curvature spacetime. We demonstrate this effect explicitly by studying gravitational solutions with non-zero cosmological constant. We show that, when the background is flat, the constant charge density filling all space in the gauge theory that has been observed in previous works is a consequence of this curvature term. As an example of a solution with a curved background, we study the Lifshitz black hole with two different matter couplings. The curvature of the background, i.e., the Lifshitz spacetime, again yields a constant charge density; however, unlike the previous examples, it is canceled by the contribution from the matter fields. For one of the matter couplings, there remains no additional non-localized source term, providing an example for a non-vacuum gravity solution corresponding to a vacuum gauge theory solution in arbitrary dimensions.

Control of climate on soil charge characteristics through organic matter and clay mineral distributions in volcanic soils of Mt. Kilimanjaro, Tanzania

ABSTRACT The soil cation exchange capacity (CEC), which is contributed by constant and variable charges, is a vital indicator of soil fertility and affects elemental cycling. Climate is expected to affect soil CEC by controlling soil secondary minerals and organic matter distributions. The objective of this study was to clarify the effects of climate on the charge characteristics of the soil in Mt. Kilimanjaro under diverse climatic conditions. The soils of 15 soil profiles from southeast and northwest slopes of Mt. Kilimanjaro along the elevation gradient (910–2800 m asl.) were collected. The soil physicochemical and mineralogical properties, including constant and variable charge densities, were determined. Climate data for the study site was obtained from the WorldClim database. The results showed that the contribution of the variable charge to CEC was high at the humid sites of the elevated area of the southeast slope. At the humid sites, the high content of organic matter, which was considered to be stabilized as organo-mineral complexes by nanocrystalline minerals, enlarged the soil CEC, being more evident at cool high elevation sites. On the other hand, at the dry sites on the northwest slope and low elevations of the southeast slope, the constant charge and variable charge contributed equally to the CEC. The variable charge from organo-mineral complexes was smaller due to the progressive crystallization of nanocrystalline minerals under the dry condition, and the formed crystalline clay minerals would contribute to constant charge density. Our study indicates the importance of moisture in addition to temperature as factors that influence the distribution of organic matter and crystalline clay minerals, which in turn control the soil charge characteristics. Thus, the constant charge from crystalline clay minerals should be considered in addition to the variable charge when studying the weakly weathered volcanic soils in the relatively dry regions.

Electrochemical and mechanical performance of reduced graphene oxide, conductive hydrogel, and electrodeposited Pt–Ir coated electrodes: an active in vitro study

Objective. To systematically compare the in vitro electrochemical and mechanical properties of several electrode coatings that have been reported to increase the efficacy of medical bionics devices by increasing the amount of charge that can be delivered safely to the target neural tissue. Approach. Smooth platinum (Pt) ring and disc electrodes were coated with reduced graphene oxide, conductive hydrogel, or electrodeposited Pt–Ir. Electrodes with coatings were compared with uncoated smooth Pt electrodes before and after an in vitro accelerated aging protocol. The various coatings were compared mechanically using the adhesion-by-tape test. Electrodes were stimulated in saline for 24 hours/day 7 days/week for 21 d at 85 °C (1.6-year equivalence) at a constant charge density of 200 µC/cm2/phase. Electrodes were graded on surface corrosion and trace analysis of Pt in the electrolyte after aging. Electrochemical measurements performed before, during, and after aging included electrochemical impedance spectroscopy, cyclic voltammetry, and charge injection limit and impedance from voltage transient recordings. Main results. All three coatings adhered well to smooth Pt and exhibited electrochemical advantage over smooth Pt electrodes prior to aging. After aging, graphene coated electrodes displayed a stimulation-induced increase in impedance and reduction in the charge injection limit (p < 0.001), alongside extensive corrosion and release of Pt into the electrolyte. In contrast, both conductive hydrogel and Pt–Ir coated electrodes had smaller impedances and larger charge injection limits than smooth Pt electrodes (p < 0.001) following aging regardless of the stimulus level and with little evidence of corrosion or Pt dissolution. Significance. This study rigorously tested the mechanical and electrochemical performance of electrode coatings in vitro and provided suitable candidates for future in vivo testing.

The adhesional electrification force between randomly rough surfaces with identical materials

I present a general theory for the adhesional electrification and find a necessary force to separate two identical rough plates. This theory is a continuation of the previous research. In addition to the effect of the fluctuations of charge density, the roughness effects of two identical plates are considered. When both surfaces are rough but uncorrelated results an increase in the electroadhesion force in comparison to the case of only one rough surface. The roughness leads to an increase in the area of the rough surfaces as well as the magnitude of the positive and negative charges on the surfaces and this leads effectively to a larger charge induction. Therefore, the electroadhesion force increases between two rough plates by growing the magnitude of charges on the surfaces. When there is a cross correlation between two surfaces, the perturbed force is different from the case where there is no cross correlation between two surfaces for the constant charge density. As a result, if the cross correlation between two surfaces is positive (negative), the perturbed force is smaller (larger) than the case of two uncorrelated rough surfaces.

Optical manifestations of domains with constant topological charge density

Domains of finite topological charge density can exist in chiral materials and chiral matter. Spatial and temporal variation of the average topological charge density, represented by the $\theta$-field, induces anomalous currents that are responsible for the chiral magnetic effect, the anomalous Hall effect and other phenomena that are intimately related to the chiral anomaly. We consider domains with constant average topological charge density. We argue that even though the Maxwell equations in the bulk are not altered, the chiral anomaly manifests itself by the way of the boundary conditions. This is illustrated by several examples. The first example deals with the refraction of plane electromagnetic wave on a surface of a constant-$\theta$ domain. We derive the modified Fresnel equations and discuss the effect of the chiral anomaly on the amplitude and polarization of the reflected and transmitted waves. In particular, we argue that the Brewster's angle is sensitive to the value of $\theta$. In the second example we compute the spectrum of the transition radiation at high frequencies and show that it is enhanced at finite $\theta$.

Tribological Properties of Oxide Coatings Produced on EN AW-5251 Alloy using Different Distances between Electrodes

Abstract The subject of the presented work was the analysis of the influence of the distance between the electrodes using in the coating process on the tribological properties of oxide coatings. Oxide coatings were prepared on EN AW-5251 aluminum alloy samples. The samples surfaces were subjected to hard anodizing process in a multicomponent electrolyte based on sulfuric acid with an addition of organic acids. Anodizing was carried out with a constant electric charge density of 180 A·min/dm2. The distances between the electrodes for subsequent samples increased every 0.125 m up to 1 m. The tribological partner in a sliding couple with oxide layers was pin of PEEK/BG. Tribological tests were conducted on a T-17 tester in reciprocating motion, in technically dry friction conditions. Before and after tribological test, examination of the geometrical structure of counter-specimens’ surface was carried out using the Form Talysurf contact profilographometer, via a 3D method. The most satisfactory tribological parameters were obtained for the PEEK/BG association with the coating produced at a distance between the electrodes equal to 0.25 m.

Contact electrification between randomly rough surfaces with identical materials

We put a flat and a rough surface in contact and then separate them by the distance d. We calculate the work and the force needed to separate two surfaces. The theory is an extension of earlier researches by Persson, Scaraggi, and Volokitin. In addition to the effects of the roughness, we consider the effect of the fluctuations of charge density in the work of adhesion. The roughness increases the area of the surface and, consequently, an enhancement in the charge, growth in the force, and work of adhesion. When the density of charges is not constant, the roughness imposes a balanced distance between plates. As the balanced distance decreases, the roughness of the surface increases. To reach the distance less than the balanced, a downward force is needed. The comparison between the force of constant charge density and fluctuations of charges displays that the force of charge fluctuations has the larger magnitude than the constant charge, even with a charge density power spectrum 10−13 less than the square of the constant charge density.

Exploring the structural and electronic properties of double-Fe atom-doped Si20 cluster by quantum chemical calculations

We carried out a quantum chemical investigation on the structural and electronic properties of double-Fe atom-doped Si20 cluster by density functional theory calculations. The results showed that anionic, neutral, and cationic Fe2Si20 have similar Frank–Kasper structures, constructed by Si4 rhombuses, Si5 pentagons, and Si6 hexagons. More interestingly, Fe2Si20− shows superhalogen properties. The Fe–Fe interactions in Fe2Si 20 −/0/+ (the meaning of the acronym: Fe2Si 20 −/0/+ refers to Fe2Si20 cluster with a negative charge, neutral state, and a positive charge, respectively.) are weak, further verified by constant electronic charge densities, molecular orbital, and PDOS analyses. The bonding interactions between atoms are in the sequence of Si–Si > Fe–Si > Fe–Fe. Moreover, Fe2Si20−, Fe2Si20, and Fe2Si20+ are all significantly aromatic.

Enhanced electroosmotic flow and ion selectivity in a channel patterned with periodically arranged polyelectrolyte-filled grooves

An enhanced electroosmotic flow through a surface-modulated microchannel is considered. The microchannel is modulated by periodically arranged rectangular grooves filled with polyelectrolyte materials. The flat surface of the walls is maintained at a constant charge density. A nonlinear model based on the Poisson–Nernst–Planck equations coupled with the Darcy–Brinkman–Forchheimer equation in the polyelectrolyte region and Navier–Stokes equations in the clear fluid region is adopted. Going beyond the widely employed Debye–Huckel linearization, we adopt numerical methods to elucidate the effect of pertinent parameters on electroosmosis in the patterned channel. The patterned microchannel results in an enhancement in the average EOF by creating an intrinsic velocity slip at the polyelectrolyte–liquid interface. An analytical solution of the EOF for a limiting case in which the groove width is much higher than the channel height is obtained based on the Debye–Huckel approximation. This analytical solution is in good agreement with the present numerical model when a low charge density and a thin Debye layer are considered. We have also established an analogy between the EOF in a polyelectrolyte-filled grooved-channel with the EOF in which the grooves are replaced by the charged slipping planes.

Dynamical fluxionality, multiplicity of structural forms, and electronic properties of the B3Si11 cluster: anion photoelectron spectroscopy and theoretical calculations.

The geometrical structures and electronic properties of anionic, neutral, and cationic B3Si11 clusters were investigated by performing ab initio calculations combined with size-selected anion photoelectron spectroscopy. The experimental photoelectron spectrum of the B3Si11- anion is reasonably reproduced by theoretical simulations of two competing isomers. The global minimum of the B3Si11- anion is formed by the fusion of a B3Si7 bicapped tetragonal antiprism to a B3Si4 pentagonal bipyramid by sharing a B3 triangle, while that of neutral B3Si11 has a B3-endohedral sandwich structure composed of a Si5 five-membered ring and a Si6 six-membered ring, and that of the B3Si11+ cation adopts a Si11 tricapped tetragonal antiprism with three face-capping B atoms. It is interesting that a Si5 five-membered ring and a Si6 six-membered ring are stabilized by three B atoms in B3Si11. The three B atoms tend to bond with each other to form a B3 triangle with stronger B-B bonds than B-Si bonds. Moreover, neutral B3Si11 exhibits σ + π double delocalized bonding patterns. Anionic, neutral, and cationic B3Si11 clusters have multiplicity of structural forms and their low-lying isomers show dynamical fluxionality. The bond lengths, bond orders, MO, constant electronic charge density surfaces, and PDOS analyses showed that the three B atoms in B3Si11 have strong bonding interactions.