• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.179-180
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• 2008

In this paper, the variable tendency piezoelectric constant and resonance characteristics piezoelectric ceramics due to the electric field is studied. The practical application of piezoelectric ceramics is not only applied in field of small signal. For example, in case of an ultrasonic motor, $120{\sim}130Vrms$ of driving voltage is needed and that of an piezoelectric pump, $200{\sim}220Vrms$ of voltage is required. Therefore, to examine the characteristics of piezoelectric ceramics in large signal contributes to reducing the susceptibility to the multifarious application and securing the ease of the production of control circuit. These contributions may be connected to the expansion of industrial application. We fabricated disk-type piezoelectric ceramic samples by using conventional method and measured the resonance characteristics of these samples under from low to high voltage driving conditions. According to increasing the value of the input voltage, we measured the resonance frequency of the piezoelectric ceramic, and inquired into the cause of these phenomena.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.144-149
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• 2003

Carbon tips were grown on Si cantilevers by applying an electron beam to them directly with Scanning Electron Microscope. A carbon tip was fabricated by aligning the electron beam directly down the vertical axis of Si cantilever and then irradiating a single spot on the cantilever for a proper time in the dominant atmosphere of residual gases generated by the oil of the diffusion pump. A number of control parameters for SEM, including exposure time, acceleration voltage, emission current, and beam probe current, were allowed to make various aspect ratio feature. The growth of carbon tips was not affected by the surface morphology of substrates. We could acquired the tip whose effective length is 0.5 $\mu\textrm{m}$, bottom diameter is 90 nm and cone half angle $3.5^{\circ}$ The growth technique of the high aspect ratio carbon tips on the tip-free cantilevers is available to reduce the complexities of fabricating sub-micron scale tips on the PZT thin film actuator integrated AFM cantilevers.