Development of a levitated micromotor for application as a gyroscope

Shearwood, C.; Ho, Kong-Weng; Williams, C.B.; Gong, Huaping

doi:10.1016/s0924-4247(00)00292-2

Cited by 95 publications

(62 citation statements)

References 13 publications

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“…According to Faraday's law, the electromotive force (EMF) induced in the PM is proportional to the rate of change of the excitation magnetic flux: the higher the frequency of the input current, the larger the EMF. Increasing the frequency, the skin depth effect becomes dominant, as has been experimentally reported for the 2D MIS in [8,9,18].…”

Section: Methodssupporting

confidence: 67%

“…In order to compare the levitation effects of 3D MIS to 2D MIS, we scaled up the 2D MIS reported in [8] to the same diameter of our 3D MIS. Using this scaled up 2D MIS, COMSOL simulation shows that it needs 12 −times more input current compared to our 3D MIS (140 mA at 8 MHz) to levitate the same PM at the same height.…”

Section: Methodsmentioning

confidence: 99%

“…The operating principle has been described in detail in the previous work from Shearwood [8], as well as in our own earlier contribution [11]. Briefly, the 3D MIS consists of two coaxial wire bonded coils, as shown in Figure 1.…”

Section: Operating Principlementioning

confidence: 99%

“…The inductance of the single-layer coil far left from the resonant frequency was measured to be 1.16 µH, with the resonant frequency of 111 MHz. The inductance of the 2D MIS in [8] with the same size in diameter was only about 10 nH and a resonant frequency of 15 GHz according to simulations carried out with Agilent Advanced Design Systems. The repeatability of coil electrical parameters for single-layer coils was reported to be excellent in [5].…”

Section: Coil Impedance and Designmentioning

confidence: 99%

“…A 400 µm diameter Al PM of 12 µm thickness was levitated at a height of 30 µm with a current root mean square (RMS) value of 600 mA at 10 MHz using planar microcoils. A micro-gyroscope based on this prototype was demonstrated five years later [8] employing three different coils for levitation, stabilization and rotation, respectively, all of them integrated as one single planar structure. A second input signal was superimposed on the coil for PM rotation.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Performance Characterization of Micromachined Inductive Suspensions Based on 3D Wire-Bonded Microcoils

Poletkin

Wallrabe

et al. 2014

Micromachines

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We present a comprehensive experimental investigation of a micromachined inductive suspension (MIS) based on 3D wire-bonded microcoils. A theoretical model has been developed to predict the levitation height of the disc-shaped proof mass (PM), which has good agreement with the experimental results. The 3D MIS consists of two coaxial wire-bonded coils, the inner coil being used for levitation, while the outer coil for the stabilization of the PM. The levitation behavior is mapped with respect to the input parameters of the excitation currents applied to the levitation and stabilization coil, respectively: amplitude and frequency. At the same time, the levitation is investigated with respect to various thickness values (12.5 to 50 µm) and two materials (Al and Cu) of the proof mass. An important characteristic of an MIS, which determines its suitability for various applications, such as, e.g., micro-motors, is the dynamics in the lateral direction. We experimentally study the lateral stabilization force acting on the PM as a function of the linear displacement. The analysis of this dependency allows us to define a transition between stable and unstable levitation behavior. From an energetic point of view, this transition corresponds to the local maximum of the MIS potential energy. 2D simulations of the potential energy help us predict the location of this maximum, which is proven to be in good agreement with the experiment. Additionally, we map the temperature distribution for Micromachines 2014, 5 1470 the coils, as well as for the PM levitated at 120 µm, which confirms the significant reduction of the heat dissipation in the MIS based on 3D microcoils compared to the planar topology.

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Section: Methodssupporting

confidence: 67%

Section: Methodsmentioning

confidence: 99%