Enhancing higher-order modal response in multifrequency atomic force microscopy with a coupled cantilever system

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• Multifrequency atomic force microscopy (AFM) relies on cantilever multimode operation for high-resolution imaging and property extraction.
• Traditional rectangular cantilevers exhibit weak higher-order modal responses in air, limiting multifrequency AFM sensitivity.
• Previous research proposed a bridge/cantilever coupled system to enhance these modal responses, offering a simpler and more cost-effective solution.

Purpose of the Study:

• To comprehensively investigate the bridge/cantilever coupled system's modal response, considering probe and excitation surface sizes.
• To experimentally validate the effectiveness and identify optimal conditions for the coupled system in practical AFM applications.
• To quantify the enhancement in higher-order modal response compared to traditional cantilevers.

Main Methods:

• Development of a macroscale experimental platform to study the coupled system.
• Finite element analysis (FEA) and experimental measurements to compare coupled systems with traditional cantilevers.
• Investigation of the influence of probe and excitation surface sizes on modal response.

Main Results:

• The coupled system significantly enhances the higher-order modal response of cantilevers compared to traditional designs.
• Finite element analysis and experimental results confirm the effectiveness of the coupled system.
• Optimal conditions for enhancing macroscale cantilever modal response were identified.

Conclusions:

• The bridge/cantilever coupled system offers a practical and cost-effective method to improve multifrequency AFM sensitivity.
• The system increases modal frequencies and introduces additional resonance peaks, demonstrating its versatility.
• This enhanced system holds significant potential for diverse applications within atomic force microscopy.