Masataka Urago

Voltage required to detach an adhered particle by Coulomb interaction for micromanipulation

An adhered particle can be detached by Coulomb interaction. The voltage required for detachment for micromanipulation is theoretically analyzed by employment of a boundary element method. The system consists of a manipulating probe, a spherical particle, and a substrate plate, all of these objects being conductive. The manipulator and the substrate are cylindrical, and axial symmetry is assumed. Although a numerical method is used to solve the equations, all parameters are normalized. The effect of the shape parameters on the Coulomb force is systematically calculated. The force is independent of system size and depends on the relative shape of the system. The force is proportional to the applied voltage raised to the second power. The force generated by the Coulomb interaction is compared with the adhesion force deduced from the Johnson–Kendall–Roberts theory, and the voltage required for detachment is clearly expressed. The possibilities and limitations of micromanipulation using both the adhesion pheno...

Kinetic control of a particle by voltage sequence for a nonimpact electrostatic micromanipulation

This letter describes a calculation of a voltage sequence to obtain kinetic control of a particle for nonimpact electrostatic micromanipulation. The system consists of conductive objects: A manipulation probe, a spherical particle, and a substrate plate. The particle, initially adhering to the probe tip, is detached by an applied voltage. The electrostatic force acting on the particle during its movement to the substrate is calculated by a numerical boundary element method. We determine the voltage and time sequence for nonimpact deposition of the particle onto the substrate by considering the total work to the particle. The calculation provides the power source requirements for nonimpact particle deposition.

Fast multipole boundary element method using the binary tree structure with tight bounds: application to a calculation of an electrostatic force for the manipulation of a metal micro particle☆

Abstract Boundary element method is one of the most powerful tools to solve partial differential equations. However, it takes a lot of computational time when applied to an actual problem with a large number of unknowns. In this research, the binary tree structure with tight bounds and the downward pass for this structure are adopted for the fast multipole method to reduce the number of M2L translations, thereby further reducing the computational time. Furthermore, the recurrence formulae to calculate the multipole moments of a triangular element are derived. The fast multipole boundary element method using the binary tree structure with tight bounds is developed and the analyses of an electrostatic force acting on a metal micro particle above a complex structure are performed to confirm the effectiveness of this method.

Oblique Propagation of Time Harmonic Waves in Periodic Piezoelectric Composite Layered Structures

Piezoelectric material has played an important role of the modern engineering such as ultrasonic transducers, ultrasonic receivers, ultrasonic motors, SAW devices and crystal oscillators to date. An elastic wave analysis of the material is indispensable to enlarge the applicability of the material. In this paper, we investigate a plane-like SH wave obliquely propagating through a periodic piezoelectric composite layered structure and derive a dispersion relation of the wave.

Non-impact electrostatic micromanipulation by voltage sequence for time

This paper proposes how to determine a voltage sequence for time to realize a non-impact electrostatic micromanipulation by kinetic control of a detached particle. The system consists of a manipulation probe, a spherical microparticle, and a substrate plate. These objects are all conductive. The particle initially sticks to the probe tip due to adhesional force and is detached by the applied voltage. The force on the particle, which is generated by electrostatic interaction, is evaluated through a boundary element method. Although the numerical method is used, all the parameters are normalized. Based on the evaluation, we propose the simple method by accelerating and decelerating voltage, and clearly express the conditions of voltage and time by considering the total work to the particle during its flight. The discussion about the time reveals the feasibility of the method from the viewpoint of the through-rate of a power-source.