Ground Geometries Research Articles

A Study of the Electronic Absorption and Emission Spectra of DBDMA Dye: Solvent Effect, Energy Transfer, and Fluorescence Quenching

This study is aimed to shed light on the electronic absorption and emission spectra of DBDMA (2-(1-(difluoroboraneyl)-1,2-dihydroquinolin-2-yl)-2-(1-methylquinoxalin-2-ylidene) acetonitrile) in different solvents. Both types of spectra were obtained theoretically and produced experimentally in different solvents. The photostability of dye was tested, and its energy transfer behavior in the presence of oxygen and hydrated copper sulfate quenchers was investigated. We also gave a qualitative estimation of the effect of acidic media on the absorption and emission spectra. There is good compatibility between the calculated and measured values of many photophysical parameters. DBDMA has a low chemical quantum yield in solvents of different polarities, and the fluorescence quantum yield is high enough, which confirms, together with the low values of the excited state lifetime, its efficiency as laser emitting dye in the range of wavelength emission maxima. The rigidity of the DBDMA molecule is the main reason for the photochemical stability and the absence of a considerable shift as a result of the change in the polarity of the solvents. Geometries of ground and excited states were optimized using the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT), respectively. Upon using the TD-DFT method, the UV-Vis absorption and emission spectra of the DBDMA molecule in different solvents were illustrated. A slight change is observed in the position of the maximum emission and absorption wavelength with the change of the solvent due to the rigidity of the compound. There was no apparent effect of quenching by oxygen. Besides, no intersystem crossing (ISC) was observed for the excited state of the DBDMA as a result of aeration of a solution with O2 for 20 min, which was an explanation of the stability of peak emission intensity of dye after exposure to oxygen gas. The energy transfer rate constant has been calculated as well.

Synthesis and characterization of blue-violet emitting iridium(III) complex coordinated via chlorinated ancillary ligand

Refluxing HL [5-chloro-2-((2-hydroxynaphthalen-1-yl)diazenyl)phenyl)(phenyl)methanone] with [(2-ppy)2Ir(μ-Cl)]2 in ethanol-dichloromethane mixture in the presence of a base (NEt3) afforded complex of composition [Ir(2-ppy)2(L)], where the azo-ligand is coordinated to iridium(III) center as monoanionic bidentate N,O-donors. The ligand and complex were characterized unequivocally. Molecular structures of both the ligand and complex were confirmed by single-crystal X-ray diffraction. The ground and excited-state geometries, absorption, and emission properties of the iridium(III) complex were further examined by DFT and TD-DFT methods. The complex exhibits a blue-violet emission band at 395 nm with quantum yield (Φ) 0.06. Experimental and theoretical studies support the fact that the nature of emission is an admixture of 3IL and 3MLCT state.

Platinum(II) coordination compound with 4′-[4-(dimethylamino)phenyl]-2,2′:6′,2″-terpyridine – The new insight into the luminescence behavior and substituent effect

{PtCl[4′-(4-NMe2)-Ph-terpy-κ3N]}BPh4·CH3CN (1) was synthesized and its structural, electrochemical and photophysical properties were characterized in comparison to previously described systems of [PtCl(4′-Ph-terpy-κ3N)]+ and [PtCl(4′-NMe2-terpy-κ3N)]+ to determine again the significance of the appropriate design of substituent in case of luminescence behavior of transition metal complex. The molecular formula of compound was confirmed by.X-ray analysis, elemental analysis, FT-IR and NMR studies. The geometries of ground and excited states of compound were also calculated on the basis of Density Functional Theory (DFT) method. The electrochemical properties were elucidated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electronic absorption spectra of compound (1) in solutions are similar to those in described previously platinum(II) terpyridine coordination compounds. The photoluminescence properties were studied in various media to rationalize effects on emission properties caused by substituent, solvent polarity, concentration of solution and rigidity of media. The studied compound displays enhancement of photoluminescence properties in comparison to [PtCl(terpy-κ3N)]+ system, however its emission lifetime in the regard to [PtCl(4′-Ph-terpy-κ3N)]+ and [PtCl(4′-NMe2-terpy-κ3N)]+ is significantly decreased. This suggest the impeded charge transfer from electron-rich NMe2 group via phenylene bridge to the terpy core due to the unfavorable, inclined geometry of excited state. As a consequence of substituent twisting on the path S0 → S1 → T1, the interference of 3ILCT and 3MLCT excited state is disturbed favouring the non-radiative deactivation process of {PtCl[4′-(4-NMe2)-Ph-terpy-κ3N]}BPh4·CH3CN.

Influence of Gamma-Irradiation on Structural, Optical and Photocatalytic Performance of TiO2 Nanoparticles Under Controlled Atmospheres

The effect of gamma-rays on structural, optical and photocatalytic properties of TiO2 nanoparticles under controlled atmospheres are studied to further improve photocatalytic performance. The sol–gel TiO2 powders were deposited with spin-coating technique, annealed at 500°C then finally irradiated by gamma-rays. The structural and optical characteristics of samples were investigated by Fourier transform infrared spectroscopy, x-ray diffraction and UV-visible spectroscopy (UV). The time-dependent density functional theory (TD-DFT) calculation are used to determine ground geometries and electronic structures of TiO2 nanostructures. DFT calculations present an excellent conformity with experimental results, and a high anisotropy in stretched thermal and electrical conductivity TiO2 nanostructures was found. Structural and optical results show that gamma radiation did not change the crystallinity of TiO2 nanostructures and leads to an optical band gap reduction to 3.039 eV. The gamma radiation effect on photocatalytic performance was investigated by methylene blue degradation as a typical pollutant. Gamma radiation has been discovered to improve considerably the degradation of pollutants compared with unirradiated TiO2.

Using a 3-Dimensional Industrial Vehicle Model on Arbitrary Ground Geometries

Dynamic driving assistance functions are beginning to enjoy popularity in the sector of industrial vehicles. Many such functions rely on a precise model of the vehicle dynamics. In consideration of the usage scenarios (e.g. intralogistics) and specific properties of industrial vehicles, common simplified dynamics models for passenger cars and highway trucks are not suitable for an accurate description of the vehicle behavior.In this work the relevant requirements are determined and a dynamic model for an industrial vehicle is presented. The model includes a kinematic description of the suspension, a flexible tire-ground interaction model for various ground surface profiles and supports trailer coupling forces with coupling backlash. Simulations of exemplary scenarios are used to verify the proposed vehicle model.

A comparative study of DFT calculated and experimental UV/Visible spectra for thirty carboline and carbazole based compounds

A comparative study of UV/Visible spectra of carboline and carbazole derivatives was conducted by employing the Density Functional Theory (DFT) approach. In this study, the geometries of ground and excited states, excitation energy and absorption spectra were estimated by using seven different DFT functional; CAM-B3LYP, B3LYP, MPW1PW91, PBE, B3PW91, WB97XD and HSE06 with 6-31G basis set. Moreover, five different basis sets 3-21G, 6-31G, DGDZVP, DGTZVP and SDD were also investigated with the CAM-B3LYP and WB97XD functional to take out the best combination of functional and basis set. CAM-B3LYP/6-31G and WB97XD/DGDZVP combination were found to have closest agreement with the experimental values of β-carboline derivatives and carbazole derivatives, respectively. This study provided an insight about the electronic characteristics of the selected compounds and provided an effective tool for developing and designing the better UV absorber compounds.

Benchmark study of UV/Visible spectra of coumarin derivatives by computational approach

A benchmark study of UV/Visible spectra of Simple coumarins and Furanocoumarins derivatives was conducted by employing the Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT) approaches. In this study the geometries of ground and excited states, excitation energy and absorption spectra were estimated by using the DFT functional CAM-B3LYP, WB97XD, HSEH1PBE, MPW1PW91 and TD-B3LYP with 6-31 + G (d,p) basis set. CAM-B3LYP functional was found to have close agreement with the experimental values of Furranocoumarin class of coumarins while MPW1PW91 gave close results for simple coumarins. This study provided an insight about the electronic characteristics of the selected compounds and provided an effective tool for developing and designing the better UV absorber compounds.

An integrated model of tool grinding: challenges, chances and limits of predicting process dynamics

The objective of manufacturing technology, to reduce machining costs, increase product quality and optimize process setups, is only achievable by considering the entire manufacturing process and its interrelations. Especially in tool grinding, strong interactions exist between workpiece dynamics, grinding wheel engagement, structure deformations and cutting process conditions, which makes an integrated model necessary. This paper introduces a tool grinding model that combines time-dependent dynamical aspects of the grinding wheel and workpiece with local varying contact conditions to predict the final workpiece geometry and cutting forces with a high resolution in space and time. The model is capable to reproduce systemic effects on cutting forces and ground geometries which only occurs in the interplay of all system components. The model is also positively tested in representing influences of process parameters and in optimizing the machining. The excellent agreement of simulations and experimental data shows the model’s potential in manufacturing technology, but also in investigating grinding aspects, which are not fully understood yet.

A model-scale study to assess the influence of ground geometries on aerodynamic flow development around a train

The need for interoperability for rail operators across Europe has resulted in the development of the technical specifications for interoperability: requirements and regulations which include safety limits for train aerodynamics. Safety limits are calculated within guidelines, including environmental conditions, train speeds and ballast shoulder height. However, there are many cases on the European rail network which fall outside ballast shoulder height limits, raising questions about the suitability of the technical specifications for interoperability limits, where European homologation is a requirement. Ballast is a layer of crushed stone onto which the railway track is laid; a ballast shoulder is defined from the top of the ballast layer to the base of the track foundation or ground. This paper describes the detailed model-scale experiments carried out at the University of Birmingham’s moving model TRAIN rig facility to assess the influence of ground geometries on aerodynamic flow development around a train. The technical specifications for interoperability methodology was questioned in relation to whether modest changes to include a wider cross-section of ballast shoulder heights, more appropriate to actual operating conditions, would affect limit values in relation to safety. The influence of ballast shoulder height was investigated for three typical train types. The results showed a similar static pressure development for all the ballast shoulder heights tested. Passenger train results indicated that shallow ballast shoulders confine the aerodynamic flow within a smaller area, increasing the magnitude of slipstream velocities in respect to larger ballast shoulders. The largest slipstream velocities were found for the ground configuration with no ballast shoulder modelled. Measurements within the technical specifications for interoperability-specified range of ballast shoulder heights exhibited little difference in flow development. Analysis of maximum 1 s gusts, calculated using the current technical specifications for interoperability methodology, found values lie close to, but do not break, the existing limits. Increasing ballast shoulder height was shown to decrease values away from technical specifications for interoperability limits.

Time-dependent density functional theory study of the luminescence properties of gold phosphine thiolate complexes.

The origin of the emission of the gold phosphine thiolate complex (TPA)AuSCH(CH3)2 (TPA = 1,3,5-triaza-7-phosphaadamantanetriylphosphine) is investigated using time-dependent density functional theory (TDDFT). This system absorbs light at 3.6 eV, which corresponds mostly to a ligand-to-metal transition with some interligand character. The P-Au-S angle decreases upon relaxation in the S1 and T1 states. Our calculations show that these two states are strongly spin-orbit coupled at the ground state geometry. Ligand effects on the optical properties of this complex are also discussed by looking at the simple AuP(CH3)3SCH3 complex. The excitation energies differ by several tenths of an electronvolt. Excited state optimizations show that the excited singlet and triplet of the (TPA)AuSCH(CH3)2 complex are bent. On the other hand, the Au-S bond breaks in the excited state for the simple complex, and TDDFT is no longer an adequate method. The excited state energy landscape of gold phosphine thiolate systems is very complex, with several state crossings. This study also shows that the formation of the [(TPA)AuSCH(CH3)2]2 dimer is favorable in the ground state. The inclusion of dispersion interactions in the calculations affects the optimized geometries of both ground and excited states. Upon excitation, the formation of a Au-Au bond occurs, which results in an increase in energy of the low energy excited states in comparison to the monomer. The experimentally observed emission of the (TPA)AuSCH(CH3)2 complex at 1.86 eV cannot be unambiguously assigned and may originate from several excited states.

Tuning the spectroscopic properties of aryl carotenoids by slight changes in structure.

Two carotenoids with aryl rings were studied by femtosecond transient absorption spectroscopy and theoretical computational methods, and the results were compared with those obtained from their nonaryl counterpart, β-carotene. Although isorenieratene has more conjugated C═C bonds than β-carotene, its effective conjugation length, Neff, is shorter than of β-carotene. This is evidenced by a longer S1 lifetime and higher S1 energy of isorenieratene compared to the values for β-carotene. On the other hand, although isorenieratene and renierapurpurin have the same π-electron conjugated chain structure, Neff is different for these two carotenoids. The S1 lifetime of renierapurpurin is shorter than that of isorenieratene, indicating a longer Neff for renierapurpurin. This conclusion is also consistent with a lower S1 energy of renierapurpurin compared to those of the other carotenoids. Density functional theory (DFT) was used to calculate equilibrium geometries of ground and excited states of all studied carotenoids. The terminal ring torsion in the ground state of isorenieratene (41°) is very close to that of β-carotene (45°), but equilibration of the bond lengths within the aryl rings indicates that the each aryl ring forms its own conjugated system. This results in partial detachment of the aryl rings from the overall conjugation making Neff of isorenieratene shorter than that of β-carotene. The different position of the methyl group at the aryl ring of renierapurpurin diminishes the aryl ring torsion to ∼20°. This planarization results in a longer Neff than that of isorenieratene, rationalizing the observed differences in spectroscopic properties.

Theoretical study of the structural and optical properties of cytosine analogues

Fluorescent nucleoside analogues have attracted much attention in studying the structure and dynamics of nucleic acids in recent years. In the present work, we use theoretical calculations to investigate the structural and optical properties of four cytosine analogues (termed as C1, C2, C3, and C4), and also consider the effects of aqueous solution and base pairing. The results show that the fluorescent cytosine analogues can pair with guanosine (G) to form stable H-bonded WC base pairs. The excited state geometries of cytosine analogues are similar to the ground geometries. The absorption maxima of the cytosine analogues are greatly red shifted compared with nature cytosine (C). The calculated absorption peaks of modified deoxyribonucleosides are in good agreement with the experimental data. The solvent effects can induce a small blue shift for C1 and C2 but a little red shift for C3 and C4, and can increase the oscillator strengths in both the absorption and emission spectra. With regard to the WC base pairs, the B3LYP functional reveals that the lowest energy transitions of GC base pairs are charge transfer excitation while the CAM-B3LYP functional predicts that they are localized excitation. The M062X and CAM-B3LYP functional show good agreement with respect to both the value of the lowest energy transitions as well as the oscillator strengths.

Molecular structure, vibrational and electronic properties of 4-Phenyl-3H-1,3-thiazol-2-ol using density functional theory and comparison of drug efficacy of keto and enol forms by QSAR analysis

4-Phenyl-3H-1,3-thiazol-2-ol can exist in two tautomeric forms – keto and enol. Comprehensive investigation of molecular geometry and electronic structure in ground as well as in the first excited state of 4-Phenyl-3H-1,3-thiazol-2-ol (enol) has been carried out. To determine lowest-energy molecular conformation of the title molecule, the selected torsion angles were varied in steps of 10° and molecular energy profile was calculated from −180° to +180°. Experimental FT-IR and FT-Raman spectra of title compound were compared with the spectral data obtained by DFT/B3LYP method. Dipole moment, polarizability, first static hyperpolarizability and molecular electrostatic potential surface map have been calculated to get a better insight of the properties of title molecule. Natural bond orbital (NBO) analysis has been done to study the stability of the molecule arising from charge delocalization. UV–Vis spectrum of the title compound was also recorded and electronic properties such as frontier orbitals and band gap energies were calculated by TD-DFT approach. To compare the drug efficacy of enolic and keto forms, QSAR properties of both forms have also been computed and discussed.

The unified discrete surface Ricci flow

Ricci flow deforms the Riemannian metric proportionally to the curvature, such that the curvature evolves according to a heat diffusion process and eventually becomes constant everywhere. Ricci flow has demonstrated its great potential by solving various problems in many fields, which can be hardly handled by alternative methods so far.This work introduces the unified theoretic framework for discrete surface Ricci flow, including all the common schemes: tangential circle packing, Thurston’s circle packing, inversive distance circle packing and discrete Yamabe flow. Furthermore, this work also introduces a novel schemes, virtual radius circle packing and the mixed type schemes, under the unified framework. This work gives explicit geometric interpretation to the discrete Ricci energies for all the schemes with all back ground geometries, and the corresponding Hessian matrices.The unified frame work deepens our understanding to the discrete surface Ricci flow theory, and has inspired us to discover the new schemes, improved the flexibility and robustness of the algorithms, greatly simplified the implementation and improved the efficiency. Experimental results show the unified surface Ricci flow algorithms can handle general surfaces with different topologies, and is robust to meshes with different qualities, and is effective for solving real problems.

Theoretical study on absorption and emission spectra of adenine analogues

Fluorescent nucleoside analogues have attracted much attention in studying the structure and dynamics of nucleic acids in recent years. In the present work, we use theoretical calculations to investigate the structural and optical properties of four adenine analogues (termed as A1, A2, A3, and A4), and also consider the effects of aqueous solution and base pairing. The results show that the fluorescent adenine analogues can pair with thymine to form stable H-bonded WC base pairs. The excited geometries of both adenine analogues and WC base pairs are similar to the ground geometries. The absorption and emission maxima of adenine analogues are greatly red shifted compared with nature adenine, the oscillator strengths of A1 and A2 are stronger than A3 and A4 in both absorption and emission spectra. The calculated low-energy peaks in the absorption spectra are in good agreement with the experimental data. In general, the aqueous solution and base pairing can slightly red-shift both the absorption and emission maxima, and can increase the oscillator strengths of absorption spectra, but significantly decrease the oscillator strengths of A3 in emission spectra.

Electronic structures and spectral properties of rhenium (I) tricarbonyl cyclopenta[b]dipyridine complexes containing different aromatic ring groups

The ground geometries, frontier molecular orbitals, and absorption properties of [Re(CO)3(cpen-dpy)Cl] (cpen-dpy = cyclopenta[b]dipyridine) functionalized with different aromatic ring groups were theoretically studied. The introduction of different moieties insignificantly changed the geometric parameters of the complexes. However, the molecular orbital energy levels of the complexes with aromatic ring groups were strongly affected by the solvent molecules. The lowest lying absorption bands of all complexes had HOMO → LUMO transition configurations that resulted in the ligand-to-ligand charge transfer character. The results showed that all complexes displayed a comparative higher sensitivity within the long wavelength range with stronger oscillator strength, which can be beneficial to more efficient absorption of the solar spectrum. The calculated ionization potential and electron affinity revealed that the balanced transport of electrons and holes of 1 was more accessible, whereas 4 possessed good hole-transfer abilities.

Quantum-classical determination of stable isomers of the Li*Arn clusters

We present a quantum-classical determination of stable isomers of LiArn, clusters with both an electronic ground state and excited states of the lithium atom. The Li atom is perturbed by argon atoms in LiArn clusters. Its electronic structure obtained as the eigenfunctions of a single-electron operator describing the electron in the field of a Li+Arn core, the Li+ and Ar atoms are replaced by pseudo-potentials. These pseudo-potentials include core-polarisation operators to account for the polarisation and correlation of the inert core with the valence lithium electron (Rhouma et al., 2002). The geometry optimisation of the ground and excited states of LiArn (n = 1–12) clusters is carried out via the Basin-Hopping method of Wales et al. (Wales and Doyle, 1997; Wales and Scheraga, 1999). The geometries of the ground and ionic states of LiArn clusters were used to determine the energy of the high excited states of the neutral LiArn clusters. The variation of the excited state energies of LiArn clusters as a function of the number of argon atoms shows an approximate Rydberg character, corresponding to the picture of an excited electron surrounding an ionic cluster core, is already reached for the 3s state.

Structures and Spectroscopic Properties of [Ru(iph)(L)<sub>2</sub>]<sup>2+</sup> (L=cpy, mpy, npy) Complexes Containing Tetradentate Ligands

采用密度泛函的B3LYP和UB3LYP方法分别优化了一系列[Ru（iph）（L）2]2＋（L=cpy（1）,mpy（2）,npy（3）;其中iph为2,9-双（1′-甲基-2′-咪唑）-1,10-邻二氮杂菲,cpy为4-氰基嘧啶,mpy为4-甲基嘧啶,npy为4-氮二甲基嘧啶）配合物的基态和激发态结构.利用含时密度泛函理论（TD-DFT）方法,结合极化连续介质（PCM）模型计算了它们在丙酮溶液中的吸收和发射光谱.研究结果表明：优化得到的几何结构参数和相应的实验值符合得非常好.1和2的最高占据分子轨道主要由金属的d轨道和iph配体的π轨道构成,但是3主要占据在npy配体上,而它们的最低空轨道主要由iph配体的π反键轨道占据.因此,1和2的最低能吸收和发射属于金属到配体（MLCT）和配体内部（ILCT）的电荷转移跃迁,而3属于两个配体之间的电荷转移（LLCT）跃迁.三个配合物的最低能吸收分别在509nm（1）,527nm（2）和563nm（3）,其磷光发射分别在683nm（1）,852nm（2）和757nm（3）.这显示出通过调节L配体的π电子给予能力可以改变最低能吸收和发射的跃迁性质和发光颜色.

Structures, spectroscopic properties and redox potentials of quaterpyridyl Ru(ii) photosensitizer and its derivatives for solar energy cell: a density functional study

Scalar relativistic density functional theory (DFT) has been used to explore the spectroscopic and redox properties of Ruthenium-type photovoltaic sensitizers, trans-[Ru((R)L)(NCS)(2)] ((R)L = 4,4'''-di-R-4',4''-bis(carboxylic acid)-2,2' : 6',2'' : 6'',2'''-quaterpyridine, R = H (1), Me (2), (t)Bu (3) and COOH (4); (R)L = 4,4'''-di-R-4',4''-bis(carboxylic acid)-cycloquaterpyridine, R = COOH (5)). The geometries of the molecular ground, univalent cationic and triplet excited states of 1-5 were optimized. In complexes 1-4, the quaterpyridine ligand retains its planarity in the molecular, cationic and excited states, although the C≡N-Ru angle representing the SCN → Ru coordination approaches 180° in the univalent cationic and triplet excited states. The theoretically designed complex 5 displays a curved cycloquaterpyridine ligand with significantly distorted SCN → Ru coordination. The electron spin density distributions reveal that one electron is removed from the Ru/NCS moieties upon oxidation and the triplet excited state is due to the Ru/NCS → polypyridine charge transfer (MLCT/L'LCT). The experimental absorption spectra were well reproduced by the time-dependent DFT calculations. In the visible region, two MLCT/L'LCT absorption bands were calculated to be at 652 and 506 nm for 3, agreeing with experimental values of 637 and 515 nm, respectively. The replacement of the R- group with -COOH stabilizes the lower-energy unoccupied orbitals of π* character in the quaterpyridine ligand in 4. This results in a large red shift for these two MLCT/L'LCT bands. In contrast, the lower-energy MLCT/L'LCT peak of 5 nearly disappears due to the introduction of cycloquaterpyridine ligand. The higher energy bands in 5 however become broader and more intense. As far as absorption in the visible region is concerned, the theoretically designed 5 may be a very promising sensitizer for DSSC. In addition, the redox potentials of 1-5 were calculated and discussed, in conjunction with photosensitizers such as cis-[Ru(L(1))(2)(X)(2)] (L(1) = 4,4'-bis(carboxylic acid)-2,2'-bipyridine; X = NCS(-) (6), Cl(-) (7) and CN(-) (8)), cis-[Ru(L(1)')(2)(NCS)(2)] (L(1)' = 4,7-bis(carboxylic acid)-1,10-phenanthroline, 9), [NH(4)][Ru(L(2))(NCS)(3)] (L(2) = 4,4',4''-tris(carboxylic acid)-2,2' : 6',2''-terpyridine, 10) and [Ru(L(2))(NCS)(3)](-) (11).

Optimization of device geometry in single-plate digital microfluidics

Digital microfluidics is a popular tool for lab-on-a-chip applications and is typically implemented in one of two formats: single-plate (“open”) devices or two-plate (“closed”) devices. Single-plate devices have some advantages relative to the more common two-plate format such as faster mixing, the capacity to move larger volumes on a given footprint, and easier access to droplets for handling or optical detection. In contrast with the two-plate format, in which ground potential is generally supplied via a top electrode, in the single-plate format, many different geometries of ground wires/electrodes have been used. Until the present study, there has been no metric to determine which of these geometries is best suited for droplet actuation. Here, we present a combination of numerical simulations and experimental tests to compare six different single-plate designs. We applied finite element analysis, using the commercially available COMSOL software package to calculate the electrodynamic actuation forces in each of the different designs and used the results to optimize device design. Forces predicted by the electrodynamic model were in agreement with forces predicted using electromechanical models. More importantly, results were verified experimentally using a unique technique that permits indirect estimation of actuation forces on digital microfluidic devices. This work illustrates the promise of using numerical modeling to enhance the design and performance of digital microfluidic devices.