Structure characterisation method for ideal and non-ideal twisted plywoods

Area of Science:

• Materials Science
• Biophysics
• Liquid Crystals

Background:

• Bouligand structures, resembling cholesteric liquid crystals, are common in biological and synthetic fibrous composites.
• Characterizing these structures requires precise determination of the helix vector and pitch.
• Previous methods using oblique cuts are ambiguous due to unknown incision angles and pitch variations.

Purpose of the Study:

• To develop an efficient and unambiguous method for determining the cholesteric pitch in twisted plywood architectures.
• To address the limitations of previous techniques in characterizing spatially homogeneous and heterogeneous structures.

Main Methods:

• Utilized geometric modeling and novel visualization software.
• Developed a method to unambiguously determine the cholesteric pitch (p(x)) from plywood film analysis.
• Applied the method to films with homogeneous, heterogeneous, and two-pitch structures.

Main Results:

• Successfully determined the cholesteric pitch under both homogeneous and heterogeneous conditions.
• The new method provides unambiguous pitch determination, overcoming previous limitations.
• Demonstrated applicability to complex structures, including those with two distinct pitches.

Conclusions:

• The presented geometric modeling approach offers an efficient and unambiguous solution for characterizing cholesteric pitch in Bouligand structures.
• This method enhances the 3D reconstruction accuracy of biological and synthetic fibrous composites.
• The technique is extendable to various biological materials like cornea and cuticles.