Polyethylene glycol (PEG) is a widely studied non-ionic polymer in the context of thermophoresis . Its migration under a thermal gradient in aqueous solution is typically thermophobic (ST is positive). However, a sign change of ST upon addition of EtOH has been reported . In a poor solvent, the mass decreases the radius of PVP in a similar way, which implies that PVP may undergo similarly increased thermophilic behavior . This mechanism supported by a drastic increase in both assembly kinetics and incubation time at 14 mW and 1 mg/mL PVP10K when printing nanospheres (AuNS, 5 mM Au 0 ) in 20% EtOH (4.74s±1.02 and 0.302 µm/s) vs. pure aqueous solution (50.27s±2.77and 0.098 µm/s). The packing and arrangement of the NPs is also strongly affected by the increasing ethanol concentration (Figure ). At the same laser power and growth time (10 s), the assemblies appear more densely packed with increasing ethanol. The stark difference