Fast-responsive hydrogel as an injectable pump for rapid on-demand fluidic flow control.

ABSTRACT: Chemically synthesized functional hydrogels have been recognized as optimized soft pumps for on-demand fluidic regulation in micro-systems. However, the challenges regarding the slow responses of hydrogels have very much limited their application in effective fluidic flow control. In this study, a heterobifunctional crosslinker (4-hydroxybutyl acrylate)-enabled two-step hydrothermal phase separation process for preparing a highly porous hydrogel with fast response dynamics was investigated for the fabrication of novel microfluidic functional units, such as injectable valves and pumps. The cylinder-shaped hydrogel, with a diameter of 9?cm and a height of 2.5?cm at 25?°C, achieved a size reduction of approximately 70% in less than 30?s after the hydrogels were heated at 40?°C. By incorporating polypyrrole nanoparticles as photothermal transducers, a photo-responsive composite hydrogel was approached and exhibited a remotely triggerable fluidic regulation and pumping ability to generate significant flows, showing on-demand water-in-oil droplet generation by laser switching, whereby the droplet size could be tuned by adjusting the laser intensity and irradiation period with programmable manipulation.

SUBMITTER: Luo R 

PROVIDER: S-EPMC5533479 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature