Tilt-angle measurement of a sample stage using a capacitive liquid-based inclinometer.

Area of Science:

• Electron microscopy
• 3D imaging
• Materials science

Background:

• Accurate alignment of projection images is essential for high-quality 3D tomographic reconstruction.
• Marker-based alignment, using fiducial markers like colloidal gold, is common but ineffective with sparse markers.
• This limitation necessitates alternative alignment strategies for reliable tomographic reconstruction.

Purpose of the Study:

• To investigate the direct measurement of tilt angles for improving tomographic reconstruction quality.
• To assess the precision of a capacitive liquid-based inclinometer for tilt angle measurement in electron microscopy.
• To determine if accurate tilt angle measurement can substitute for marker-based alignment.

Main Methods:

• Utilized a commercially available capacitive liquid-based inclinometer to measure tilt angles.
• Compared the precision of the inclinometer measurements against electron microscope monitor readings.
• Performed 3D tomographic reconstructions using both methods for quality assessment.

Main Results:

• The capacitive liquid-based inclinometer provided more precise tilt angle measurements than the electron microscope monitor.
• Direct tilt angle measurement using the inclinometer yielded 3D reconstructions comparable in quality to marker-based alignment.
• This method proved effective even when fiducial markers were scarce.

Conclusions:

• Direct tilt angle measurement offers a viable alternative to marker-based alignment in tomographic reconstruction.
• Capacitive liquid-based inclinometers enhance the accuracy of tilt angle determination in electron microscopy.
• Precise tilt angle measurement is a critical factor for achieving high-quality 3D reconstructions, especially in marker-limited scenarios.