Fluid actuation and buoyancy driven oscillation by enzyme-immobilized microfluidic microcapsules

Area of Science:

• Biomimetic locomotion
• Microfluidics
• Synthetic biology

Background:

• Mimicking microorganism locomotion in fluids is challenging.
• Self-propelled synthetic systems offer insights into non-living matter motility.
• Enzyme-catalyzed reactions can power microscale systems.

Purpose of the Study:

• To develop enzyme-immobilized microcapsules (MCs) as microscale engines.
• To investigate fluid actuation controlled by MCs.
• To explore buoyancy-driven motility of MCs.

Main Methods:

• Immobilizing enzymes onto microfluidic microcapsules.
• Analyzing fluid actuation by varying substrate concentration, reaction rate, MC diameter, and population.
• Observing buoyancy-driven motility through enzymatic oxygen bubble generation.

Main Results:

• Fluid flow was successfully maneuvered by enzyme-immobilized MCs.
• Actuation parameters (substrate concentration, reaction rate, MC size, population) influenced fluid movement.
• MCs demonstrated self-propelled motility in solution, with velocity dependent on oxygen bubble generation.

Conclusions:

• Enzyme-immobilized MCs serve as effective microscale engines for fluid actuation.
• The study demonstrates a novel approach to synthetic motility inspired by biological systems.
• Oxygen bubble generation via enzymatic reactions drives self-propelled motion in microcapsules.