External Fields as Control Strategies to Promote Biomolecule Nucleation.

Acoustic, electric, and magnetic external fields have been extensively investigated as a promising non-invasive approach to control nucleation from solution. Among these approaches, light fields leveraging lasers such as non-photochemical laser-induced nucleation (NPLIN) have seen a recent surge of interest. NPLIN involves an interaction between the solute-solvent system and laser light, but takes place at wavelengths and intensities not known to invoke any photochemical phenomena. Promising applications include direct enhancement of the nucleation rate, as well as providing polymorphic control and spatial precision in initiating crystallisation. This chapter mainly reviews the current state of NPLIN research focusing on biomolecules. Secondly, this chapter discusses other external-field-based methods, albeit in much less detail. The chapter concludes with the authors' perspective on future directions of research dedicated towards biomolecule crystal nucleation using such field-based methods.