Resonance excitation method of micro-cantilever sensor

Abstract

A resonance excitation method of a micro-cantilever sensor belongs to the technical field of a micro-motor system. The micro-cantilever sensor is a capacitive micro-cantilever sensor and comprises a micro-cantilever beam base made of a n-type doped silicon material and a metal electrode arranged in parallel to the micro-cantilever beam base, wherein a tipless probe integrated with the micro-cantilever beam base and made of the same material as that of the micro-cantilever beam base is arranged at one end of the micro-cantilever beam base, and a pulse electrical signal ingoing wire and a direct-current biasing voltage ingoing wire are arranged on the micro-cantilever beam base and the metal electrode respectively. The high-frequency resonance of a micro-cantilever beam probe under the excitation with the pulse electrical signal is realized through adding the pulse electrical signal which is fractional times of a micro-cantilever beam probe resonance frequency on the micro-cantilever beam base and adding direct-current biasing voltage on the metal electrode. The resonance excitation method provided by the invention solves the problem that the high-frequency resonance of the micro-cantilever beam probe is difficult to excite, and has an important use value to the development of the micro-cantilever-based sensor.

Description

technical field [0001] The invention relates to a resonance excitation method of a micro-cantilever beam sensor, belonging to the technical field of micro-electromechanical systems. Background technique [0002] The micro-cantilever belongs to a micro-electro-mechanical system (MEMS) with a relatively simple structure, which consists of a base and probes fixed on the base. The probe is usually made of triangular or rectangular silicon or silicon nitride material. According to whether the free end of the probe is provided with a needle point perpendicular to the surface of the probe, the micro-cantilever beam can be divided into a needle-point micro-cantilever beam and a needle-free beam. micro cantilever. For a rectangular probe, its size is tens of microns to hundreds of microns in length, several microns to tens of microns in width, and one to two microns in thickness. The micro-cantilever beam probe has the mechanical characteristics of high resonance frequency and smal...

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Problems solved by technology

Their advantage is that they have a higher quality factor, and a high quality factor is of great significance for improving detection accuracy; the disadvantage is that it is difficult to achieve resonance excitation

Commonly used signal generators can only generate electrical signals with a frequency of tens of MHz. For micro-cantilever beams with high resonant frequencies, their resonant frequency cannot be reached.

Usually, the resonant excitation of the micro-cantilever beam probe is realized by an external electrical signal that is consistent with the resonant frequency. Dynamic detection, which affects the progress of scientific research

The magnetic drive detection technique (magnetomotive detection technique) can realize the excitation and detection of GHz frequency, but this technology is only applicable to the microcantilever with both ends fixed, and cannot be used for the most commonly used microcantilever with one end fixed

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