National University of Singapore – Page 3

Investigation of Metal Diffusion into Polymers via ab initio Simulations

Chen X.T., Dai L., Tan V.B.C., Wu P., Yang S.W., National University of Singapore, SG

Ab initio MD simulations were carried out to characterize the diffusion of Cu and Ta atoms/clusters inside an amorphous polymer. The diffusion coefficients of Cu and Ta atoms and their atomic clusters in linear amorphous [...]

Theoretical and Experimental Study of Synthetic MFM Tips

Han G., Wu Y.H., Zheng Y.K., National University of Singapore, SG

Recently, we have developed a synthetic MFM tip consisting of two ferromagnetic layers and a non-magnetic spacer [1]. The two ferromagnetic layers are coupled antiferromagnetically so that the MFM works in a differential detection mode. [...]

Improved O(N) Neighbor List Method Using Domain Decomposition and Data Sorting

Cheng M., Wang J-S., Yao Z-H, National University of Singapore, SG

The conventional Verlet table neighbor list algorithm is improved to reduce the number of unnecessary interatomic distance calculation in molecular simulations involving many atoms. Both of the serial and parallelized performance of molecular dynamics simulation [...]

Molecular Dynamics Simulation of Timescale Effect and Lattice Transformation of Copper Nanorod Under Bending

Liu G.R., Wang X.X., Wu H.A., National University of Singapore, SG

Mechanical behaviors of materials and structures at nanoscale are essentially different from those at macroscale, resulting from surface effect, size effect and time scale effect. In some experimental research at nanoscale, the bending displacement of [...]

Simulation of a Polymer Drop in a Shear Field with Dissipative Particle Dynamics Method

Chen S., Fan X.J., Khoo B.C., Phan-Thien N., National University of Singapore, SG

In the present study, the dynamics of polymer drops in micro channel under both steady state and transient shear flow conditions are investigated using Dissipative Particle Dynamics method. The polymer drop is made from finitely [...]

Effects of Slider-Driven Piezo-Microactuator Placements and Profiles on HGA Sway Mode

Chen S.X., Yang J.P., National University of Singapore, US

With areal recording density of hard disk drives (HDD) historically growing at an average of 60% per year, it is becoming increasingly more difficult to maintain the precise positioning required of the ever-smaller GMR heads [...]

Dynamic Analysis of an Electrostatic Micropump

Jiang T.Y., Lam K.Y., Ng T.Y., National University of Singapore, SG

In this paper, a micropump actuated by electrostatic force is dynamically analysed. Mathematical model is established to evaluate the dynamic response of the micropump. Electro-mechanical coupling effect is considered in evaluating the electrostatic force applied [...]

Optimal Design of A Tuning Fork Gyroscope and Its Testing Experiment

Chen W.T., Dong Y., Tay F.E.H., Wen Y., Yuan X., National University of Singapore, SG

The eigenfrequency of a MEMS Tuning Fork Gyroscope (TFG) is calculated using a formula derived from Rayleigh method. From this formula, the objective function for the optimal design is established. Then two methods to solve [...]

A Novel Method for the De-Embedding of S-Parameters of Double Heterojunction d-doped PHEMTs – Modeling and Measurements

Ang K.S., Chia Y.W.M., Joe J., Ng G.I., Rao R.V.V.V.J., Wang H., National University of Singapore, SG

A simple and accurate method for extracting small-signal signal equivalent circuit for double heterojunction d-doped PHEMTs was developed. The circuit elements were extracted from the S-parameters of PHEMTs. Parasitic inductances Lg, Ld and Ls were [...]

Electrostatic Spring Effect on the Dynamic Performance of Micro Resonators

Chua B.L., Francis E.H., Kumaran R., Logeeswaran V.J., National University of Singapore, SG

This paper reports on the significant discrepancy between the analytical and experimental resonant frequencies of the folded beam micro resonators. Experimental results for the resonant frequency showed a consistent 20% discrepancy over theoretical and finite [...]