The LLPS droplets in living cell such as nucleoli, P-bodies, and stress granules, are membrane-less organelles that exert a variety of biological functions 14 such as sensing, localization, and concentration of molecules, and activation or inactivation of biomolecular reactions. One of the LLPS droplets is an aqueous two-phase system droplet formed via the segregation of aqueous polymers, such as polyethylene glycol (PEG) and dextran , which is also referred to as a non-associative LLPS droplet. Another LLPS droplet is a coacervate (also called an associative LLPS droplet), which is formed via associative interactions between biopolymers. For example, intrinsically disordered regions of proteins , nucleic acid base pairings , and charged biopolymers have been reported as dominant factors for associative interactions.