A biomimetic microfluidic chip based on the bubble filtration mechanism of stomatal pore membranes

Abstract

Microfluidic chips hold vast potential for applications in fields such as DNA analysis, drug screening, cell culture and biosensing. However, microfluidic chips are susceptible to disruption and damage from bubbles. Current bubble removal methods suffer from limitations including narrow applicability, poor biocompatibility, limited bubble containment volume, low degassing rates, manufacturing complexity and integration challenges. Addressing these issues, this study presents the development of a bubble filtration microfluidic chip inspired by the stomatal pore structure in plant leaves, which prevents air propagation between conduits. Surface wettability theory and surface tension principles were utilized to investigate the mechanism of bubble filtration by plant stomatal pores. A cellulose/PVA hydrogel was introduced to enable the microfluidic chip to effectively filter bubbles. The design and in situ formation method of the bubble filtration chip were developed, and the chip was fabricated using micro-nanofabrication processes. Performance evaluation of the bubble filtration microfluidic chip demonstrated that with a gel film thickness of 20 μm, the microfluidic chip exhibits high gas leak threshold and minimal flow loss. The resulting biomimetic bubble filtration microfluidic chip features a simple structure, compact size, and independence from auxiliary equipment, making it suitable for portable microfluidic devices.