Perspective: Thermophoresis and Its Promise for Optical Patterning.

Thermophoresis, the movement of molecules and colloids under a thermal gradient, has been recently shown to be effective for localized trapping, manipulation, and even printing of colloidal particles at interfaces. However, the lack of a broader understanding of the behavior of various molecules and colloidal species poses a challenge to the ongoing development of thermophoresis as a tool for patterning and assembly. In this Perspective, we discuss the thermophoresis of colloids, highlighting the barriers to understanding and predicting these complex systems, as well as recent approaches for measuring and predicting thermophoretic behavior. Further development of thermophoresis-based patterning techniques is crucial to unlocking their potential to advance the field of optically driven colloidal assembly, and critical for the rapid, on-demand fabrication of sensors and devices.