Surface stress sensitization method for improving resonance type ultra-thin cantilever beam transducer sensitivity

Abstract

The invention relates to a method for improving surface stress sensitivity of a resonant ultrathin cantilever beam sensor, and belongs to the technical field of micro-mechanical sensing. The method is particularly characterized in that self-assembling monomolecular sensitive films capable of identifying selection specificity can be grown on the upper surface and the lower surface of an ultrathin resonant cantilever beam sensor; after specificities of sensitive molecules and target molecules to be detected are combined, interaction among the target molecules generates surface stress on the surfaces of the cantilever beam; and the combined action of the upper surface stress and the lower surface stress causes change of elasticity coefficient of the cantilever beam so as to change inherent resonance frequency of the cantilever beam, and achieve detection for the target molecules through measuring the change of the resonance frequency. Compared with the prior method for sensitivity test by using a mass adsorption method, the method for improving the surface stress sensitivity can carry out biochemical trace test, and the sensitivity can be improved by one order of magnitude. The method has the characteristics of simple principle, high sensitivity and easy realization.

Description

technical field [0001] The invention relates to a surface stress sensitive method for improving the sensitivity of a resonance type ultra-thin cantilever beam sensor. More precisely, the interaction between the target molecules adsorbed on the surface of the cantilever generates surface stress on the cantilever, which causes the resonant frequency drift of the cantilever sensor. By monitoring the resonant frequency, the detection of trace target molecules can be achieved. detection. The invention belongs to the technical field of micro-nano electromechanical sensing. Background technique [0002] Due to its simple structure, easy integration, and high sensitivity to force and mass, resonant cantilever sensors have been widely used in environmental monitoring and biochemical trace detection in recent years. [0003] In a certain resonance mode, changes in the effective mass and elastic coefficient of the cantilever beam will lead to changes in the resonance frequency. As e...

AI Technical Summary

Problems solved by technology

However, this sensitive method is not ideal for the detection of chemical gases

This is because the mass of chemical molecules is much smaller than that of biological cells, and the additional mass generated by specific binding and adsorption of chemical molecules on the cantilever is too light to cause a significant shift in the resonance frequency of the cantilever sensor. hard to detect

In order to realize the detection of chemical gas molecules, people try to improve the mass detection sensitivity of the cantilever beam sensor by continuing to reduce the size of the cantilever beam, but this method is not realistic: on the one hand, biochemical detection requires a certain surface area for specific reactions Adsorb target molecules with sufficient mass; on the other hand, in order to finally realize the on-site portable application, certain driving and detection elements need to be fabricated on the cantilever beam, which also requires that the size of the cantilever beam cannot be reduced indefinitely

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