Generation and handling of gaseous species with reduced parasitic power consumption and parasitic mass has been a growing challenge in many types of chemical reactors, including micro power sources, on-chip cell culturing systems, gas-liquid synthesis, micro flame ionization detectors, solar water splitting systems, and microbial electrolysis cells (MEC). To address this challenge, a self-circulating, self-regulating mechanism is proposed to generate gaseous species from liquid reactants on demand. The system involves little or zero parasitic power consumption and needs no discrete control system for regulation.
Intellectual Merit
This work seeks to understand the process control and dynamics of an integrated microfluidic gas generator with self-circulation and self-regulation functionalities. This work is expected to establish the engineering and scientific foundation for highly-efficient, autonomous, on-demand gas generation systems for many applications. To achieve this objective, the research efforts will first be focused on fundamental understanding of the reactive multiphase flow in a microfluidic network with the proposed self-regulation, self-circulation mechanism. Catalytic decomposition of hydrogen peroxide will be employed as a basic model system to perform the fundamental studies. The dynamics of bubble-driven liquid circulation, self-regulation, mechanism of gas/liquid separation, and reactant utilization will be experimentally investigated. A comprehensive lattice Boltzmann method (LBM) model will be used to study the physics in the gas generator. Bubble dynamics is a focus for the numerical study. The LBM model and the related numerical simulation will be used to provide benchmarks for the experiments and to guide future designs. The micro reactor configuration will then be tested on two applications: high-performance small fuel cells for portable electronics and energy reclamation/treatment of waste water by MECs. The issues related to these two particular applications will be used to establish the foundation for future commercialization.
Broader Impact
Efficient management and utilization of multiphase flow in microreactors have a broad range of applications. The successful implementation of this research could directly facilitate the development of high-energy-density power generation devices based on fuel cells, where hydrogen storage and delivery remain major technical challenges. The proposed approach may help overcome this problem by achieving autonomous pumping and control for on-demand hydrogen generation with little burden on system complexity and packaging. The work could also benefit a series of portable applications, such as portable electronics, implanted biomedical devices, and distributed microsystems with wireless communication capability. In addition, it could also benefit the development of scalable microbial electrolysis cells for hydrogen generation from renewable energy sources, while cleaning up waste water before its discharge. It is expected to further inspire similar approaches in on-chip cell culturing systems, micro flame ionization detector, solar water splitting systems, etc.
Educational efforts will benefit through the involvement of minority students from the local community. Summer camps will be organized on both campuses to provide local high school students an opportunity to explore the interdisciplinary fields of micro/nanotechnology.
