AFM-IR (Atomic Force Microscope InfraRed) is a general term for techniques based on detecting mechanical response of the AFM cantilever upon pulsed illumination of sample with IR light. AFM-IR is typically utilized for sample absorption mapping and spectroscopy of materials with relatively large absorption coefficient (polymers, organic materials, etc.).

Basic probing principle:

  1. focus pulsed IR laser light onto sample;
  2. illuminated sample absorbs IR radiation and thermally expands, exerting force on the AFM tip and stimulating cantilever motion;
  3. cantilever motion is detected using standard AFM technology, delivering thermal expansion maps and spectra for spectroscopic IR analysis.

AFM-IR principle

 
Challenge: Detecting small expansion of nanoparticle and thin films relies on the mechanical enhancement provided by a cantilever resonance. The cantilever resonance shifts depending on the local sample mechanics (e.g. sample stiffness, dissipation, etc. ) and measurement conditions, thus coupling optical and mechanical sample properties in the AFM-IR signal and resulting in:
 
thumb down poor sensitivity
thumb down misleading image contrast
thumb down mechanical artifacts
thumb down irreproducibility due to varying operating conditions

PiFM principle

Solution: neaspec’s tapping AFM-IR+ actively tracks the cantilever resonance, ensuring the maximum resonant enhancement and helping to decouple the optical sample properties from the mechanical properties, which provides:
 
thumb up best possible sensitivity
thumb up absence of mechanical artifacts in AFM-IR+ images
thumb up ability to extract pure optical interaction
thumb up excellent reproducibility

neaspec tapping AFM-IR+

List of neaspec AFM-IR technologies:
  • tapping AFM-IR+: tapping mode AFM-IR imaging & spectroscopy.
  • PTE+: contact mode AFM-IR with resonance enhanced sensitivity.
  • PTE: legacy contact mode PTE technique suitable for thick sample.

Compare different AFM-IR technologies and learn why neaspec is the market leader

neaspec tapping AFM-IR technology provides:

  • High-quality nanoscale-resolved chemical imaging

Chemical mapping with tapping AFM-IR+

  • High sensitivity even on ultrathin layers with tapping AFM-IR+ on

  • Sub-10 nm resolution demonstrated on PS-PMMA block copolymer
    PS-PMMA block copolymer
  • No mechanical artifacts in tapping AFM-IR+ images for true optical mapping & hyperspectral analysis

  • Excellent sensitivity: AFM-IR+ detects even the weakest vibrational signatures for precise chemical identification

afm-ir-plus spectra of polymer PS-PVAC co-polymer

  • Excellent reproducibility even for the weakest spectral features and fast acquisition speeds

hyperspectral imaging of PS-PVAC

Advantages & strengths of neaspec AFM-IR

simple

Simple Setup

No need for interferometric measurements and optical detection results in less capable yet simpler setup compare to s-SNOM

cost efficient

Cost Efficient

Purely mechanical detection reduces demand for the illuminating laser quality, resulting in larger compatibility and wider spectral coverage per invested money

max performance

Top Performance

neaspec is an unsurpassed expert & technological leader in light focusing onto the tip, delivering maximum performance with minimum laser power for preventing sample & tip degradation

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