Publications by authors named "Tomas Michalek"

Objectives: Long lower limbs relative to body size are thought to be an adaptation to prevent excessive increases in body temperature during running in hot climate. The advantage of long lower limbs relative to body size is usually explained by an increase in body surface area relative to mass; however, the influence of limb length on relative body surface area was shown to be minor. We aimed to experimentally test the effect of relative lower-limb length (LLL) on body temperature changes during running.

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The most popular modeling approach for dielectrophoresis (DEP) is the effective multipole (EM) method. It approximates the polarization-induced charge distribution in an object of interest by a set of multipolar moments. The Coulombic interaction of these moments with the external polarizing electric field then gives the DEP force and torque acting on the object.

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In this paper, we present a novel approach to noncontact micromanipulation by controlled dielectrophoresis (DEP). To steer micro-objects in the desired way, the solutions reported in the literature use either DEP cages or amplitude modulation of the voltages applied to the electrodes. In contrast, we modulate the phases, that is, we control the phase shifts of the voltages applied to the electrodes, which simplifies the hardware implementation and extends the set of feasible forces.

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Mathematical models of dielectrophoresis play an important role in the design of experiments, analysis of results, and even operation of some devices. In this paper, we test the accuracy of existing models in both simulations and laboratory experiments. We test the accuracy of the most common model that involves a point-dipole approximation of the induced field, when the small-particle assumption is broken.

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The paper describes a novel control strategy for simultaneous manipulation of several microscale particles over a planar microelectrode array using dielectrophoresis. The approach is based on a combination of numerical nonlinear optimization, which gives a systematic computational procedure for finding the voltages applied to the individual electrodes, and exploitation of the intrinsic noise, which compensates for the loss of controllability when two identical particles are exposed to identical forces. Although interesting on its own, the proposed functionality can also be seen as a preliminary achievement in a quest for a technique for separation of two particles.

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