Gastrointestinal peristalsis-inspired hydrogel actuators for NIR-controlled transport of viscous liquids.

Abstract

Liquid transportation is fundamentally important in microfluidics, water collection, biosensing and printing, and has attracted enormous research interest in the past decades. However, despite substantial progress, it remains a big challenge to achieve the controlled transport of viscous liquids (>100 mPa∙s) commonly existing in daily life and the chemical industry. Inspired by the gastrointestinal peristalsis of mammalians that can efficiently transport viscous chyme (viscosity up to 2,000 mPa∙s) by the synergistic combination of contraction driving force and lubrication, this paper reports the design and construction of double-layered tubular hydrogel actuators for directional transport of highly viscous liquids ranging from ∼1000 mPa∙s to >80000 mPa∙s under the control of an applied 808nm laser, which is attributed to the cooperation of outer layer contraction and water film lubrication of the inner layer. It's demonstrated that the actuators are capable of transporting polymerizing liquid whose viscosity significantly increases to ∼11182 mPa·s in 2h. This work paves a new avenue towards directional transport of highly viscous liquids, which not only expands the research scope of liquid transportation, but will spur the design of new liquid actuators with potential applications in viscous liquid-based microfluidics, artificial blood vessels, and soft robots. This article is protected by copyright. All rights reserved.