Lock-in amplifier based peak force infrared microscopy

Area of Science:

• Spectroscopy
• Nanotechnology
• Materials Science

Background:

• Nanoscale infrared (nano-IR) microscopy offers high-resolution, label-free chemical imaging below the diffraction limit.
• Peak force infrared (PFIR) microscopy is an emerging nano-IR technique providing multimodal chemical and mechanical characterization.
• Current PFIR microscopy requires specialized hardware and software, limiting its accessibility.

Purpose of the Study:

• To develop an accessible PFIR microscopy method using commercially available equipment.
• To reduce the implementation barrier for PFIR microscopy.
• To demonstrate the utility of a simplified PFIR approach for diverse samples.

Main Methods:

• Assembly of a PFIR microscope using a lock-in amplifier and generic, commercially available components.
• Non-destructive multimodal chemical and mechanical characterization.
• Operation without specialized hardware or software programming.

Main Results:

• Demonstrated successful PFIR microscopy with a lock-in amplifier-based system.
• Applied the method to heterogeneous soft matter, including polymer blends and blocks.
• Successfully imaged biological cells, such as E. coli.

Conclusions:

• A lock-in amplifier-based PFIR microscopy approach significantly lowers the entry barrier for nano-IR techniques.
• This simplified PFIR method makes advanced chemical and mechanical characterization more accessible to new users.
• The developed system offers a competitive and user-friendly alternative for nanoscale chemical imaging.