Manufacturing all-polymer laminar flow-based fuel cells

In the field of microfluidics, significant research effort has focused on developing integrated multifunctional devices which incorporate multiple fluidic, electronic, and mechanical components and chemical processes onto a small chip. Since the inception of these devices, a trend towards increased integration and system complexity has led to the development of highly integrated microchemical systems for a broad range of applications. In recent years, polymers have assumed a leading role as substrate materials for these integrated devices (Chapter 1). Polymers have a wide range of material properties, such as mechanical strength, optical transparency, chemical stability, and biocompatibility, which can be tailored to specific applications. However, to achieve widespread commercialization of these devices, manufacturing techniques must be advanced in parallel with analytical capabilities. This dissertation addresses this challenge by developing manufacturing technologies for two applications: (i) laminar flow-based fuel cells (LFFCs) and (ii) electrohydrodynamic-jet (e-jet) printing. Most LFFCs presented to date have been proof-of-concept unit cells that are not commercially viable for portable electronic applications. Transitioning from proof-of-concept, single-channel cells to a commercial multichannel system is a present challenge, and this dissertation will address manufacturing technologies to support this transition. This dissertation reports on the design and manufacture of a lightweight, all-polymer LFFC as an alternative to the heavy clamping constructions traditionally used for fuel cell stacks (Chapter 2). Characterization of this all-polymer LFFC addresses individual electrode performance before and after polymer encapsulation, by using a novel half-polymer, half-microfluidic fuel cell platform. After fabrication of a complete all-polymer fuel cell, performance is investigated as a function of cell operating parameters (Chapter 3). Fuel cell electrodes are traditionally fabricated by hand-painting or spray painting a catalyst ink onto a gas diffusion electrode or membrane, however electrodes prepared via these techniques do not always have a uniform distribution of catalyst. Recently, e-jet printing has been developed as a method to deposit a variety of chemical / biological materials with excellent precision for various applications in electronics, biotechnology, and microelectromechanical systems. Here, this dissertation will demonstrate e-jet deposition of fuel cell catalysts as a technique for achieving uniform catalyst distribution on microelectrodes (Chapter 4). E-jet has typically been performed using single capillaries as the fluid carrier however, printing speeds are rather slow and printing different inks requires syringe changes and realignment. To increase throughput, an integrated printing toolbit consisting of an array of three individually addressable e-jet nozzles will also be demonstrated (Chapter 5). Looking forward, these studies will further the development of manufacturing technologies for integrated microfluidic devices; a critical step in the commercial advancement of microfluidic platforms for a wide range of applications.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Hollinger, Adam

Contributors dc:contributor

• Kenis, Paul J.A.
• Harley, Brendan A.
• Higdon, Jonathan J.L.
• Wieckowski, Andrzej

• fuel cell
• laminar flow-based
• microfluidic
• polymer-based manufacturing
• microchemical systems
• electrohydrodynamic-jet printing

Statement dc:rights

• Copyright 2012 Adam Hollinger

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/31163

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/31163