Reproducible Fabrication of a Chamber for Birefringence Imaging: Experimental Test with Temperature-Controlled...

Liquid-liquid-crystalline phase separation (LLCPS) is an emerging class of soft-matter organization in which liquid-liquid phase separation couples with ordering. Quantitative birefringence imaging offers a powerful tool to characterize the resulting anisotropic condensates; however, reproducible measurements require sealed, evaporation-resistant chambers compatible with polarization optics. In this study, using a partially mechanized process, a simple glass-polydimethylsiloxane-glass chamber was fabricated that ensures reproducible sealing and minimizes user-dependent variability. The chamber maintained its structural integrity during multiple heating/cooling cycles, enabling the stable observation of liquid-crystalline DNA assemblies as a model LLCPS system. Abundant quantitative information was obtained from the observed birefringence characteristics, demonstrating the suitability of the chamber for quantitative analysis under controlled conditions. This versatile platform enables easy customization of surface chemistry and geometry, providing a practical foundation for future optical studies of diverse LLCPS and related soft-matter systems.