Self-powered catalytic microfluidic platforms for fluid delivery

Abstract

The realization of microfluidic platforms with liquid pumping and fluid transport independent on external power sources is the goal of a major part of research in the lab-on-chip (LOC) field. Autonomous pumping, indeed, has a strong impact on the cost, usability and portability of LOCs. In this context, power-free pumping is exploited herein by the use of chemically-responsive flexible thin membranes (TMs) as tool to push liquids inside the microchannels of a LOC platform. The assembled device consists of a closed poly(dimethylsiloxane) (PDMS) micro-chamber in which H2O2 dismutation occurs by an artificial catalase (ACat) system, evolving oxygen and generating a pressure gradient. This pressure is then used to push a liquid contained within an upper chamber and inject it into a tailored microfluidic channel. The two chambers are overlapped and separated by a PDMS TM, whose flexibility allows the conversion of the chemical energy into mechanical forces. Thanks to the fine-tuning of the reaction conditions by modulating the ACat catalyst and/or reagents concentrations, a precise control over the injection time and forces of the liquid can be achieved.