Stimuli-responsive smart hydrogels have been considered to be highly potential in versatile applications in numerous fields

such as chemical sensors and/or actuators

chemical values

artificial muscle

controlled drug delivery systems and substance separations

for which rapid responsive characteristics are highly desired. Therefore

rapid response to environmental stimuli is critical for the versatility of such smart hydrogels. This review briefly introduces the design and fabrication of stimuli-responsive smart hydrogels with rapid responsive characteristics

including three main types of smart hydrogels designed with different structures

which are open-cell porous structure

comb-type structure

and microsphere-composited structure. This review provides valuable information and guidance for rational design of novel stimuli-responsive smart hydrogels with rapid responsive characteristics.