Wish you could go days without charging your cell phone? How about getting a few extra hours use from your laptop? Soon,
you can. Micro fuel cells are the future of portable energy efficiency, and will soon be integrated into everyday use. While
there still remain a few limitations before these micro fuel cells hit the market, researchers estimate that nearly 200 million
micro fuel cells will be used within the next five years (Ozbek, 2003, 104). One use of these micro fuel cells is as a power
source for everyday electronic devices such as cell phones, personal digital assistants, and even laptop computers (Ozbek,
2003, 104). These micro fuel cells have many advantages over current batteries including higher output per area, reduced environmental
effects, and overall longer life (C.B., 2003, 5). More efficient cells are being created every day by using new materials
and innovative ideas, eliminating many of the current limitations. In today’s fast-paced, technology-driven world, batteries
will soon become an energy source of the past.
A fuel cell functions similar to any typical battery by converting stored chemical energy into electricity. The major
components of a standard battery are found within the fuel cell: an electrode and an anode, with an electrolyte connecting
the two. The electrode is positively charged and contains an oxidizer, such as oxygen, which absorbs electron current. The
anode is negatively charged and fed with a fuel, such as hydrogen, which is reduced (loses electrons). Fuel cells have also
recently been created using alternate fuels such as phosphoric acid, although hydrogen remains the primary fuel. The chemical
reaction that occurs within a fuel cell has a much higher efficiency than reactions that occur in standard alkaline batteries
(“Fuel Cell, 2003). In batteries, energy is lost through byproducts of the reaction such as heat. Fuel cells minimize
the loss of energy and thus have a greater output per area. A fuel cell the size of a standard AA battery could easily power
many common electronic devices such as CD players and cell phones (Ozbek, 2003, 104).
Hydrogen is the most abundant element within the earth and its atmosphere; its potential as a fuel source is unlimited.
The difficulty lies in extracting hydrogen from the environment, although new methods are extremely promising. When hydrogen
and oxygen are used in a fuel cell, the byproduct of the overall cell reaction is simply water. In a standard battery, there
are often environmentally-harmful byproducts produced as a result of the breakdown of the cell. Disposal of old batteries
is a huge environmental concern. Batteries contain many acids, which are extremely toxic substances. Micro fuel cells contain
hydrogen, oxygen, and water, which are much safer chemicals than those found in batteries. Micro fuel cells represent a significant
environmental upgrade over current battery sources.
Micro fuel cells exhibit overall longer life than batteries. In a fuel cell, the electrolyte can be either solid or
liquid, as long as it completes the circuit, allowing the electrical current to flow freely. In fuel cells, the choice of
electrolyte is crucial in the efficiency of the cell, especially at the micro level (Davies, Adcock, Turpin, and Rowen, 2000,
237). In batteries, corrosion caused by the internal chemical reaction can often limit the overall life of the battery. Within
modern fuel cells, the same is true; the greatest limitation is the durability of the materials used, particularly the electrolyte.
Many current fuel cells can only operate at extreme temperatures. Current research is being conducted using materials such
as titanium, stainless steel, and carbon composites to develop the most efficient overall cell (Davies, et al., 2000, 237).
In preliminary studies, the largest limitations occurred due to corrosion and internal energy loss. Thus, it is important
for researchers to use materials that will minimize corrosion while maintaining conductivity over long periods of time. In
2000, D.P. Davies conducted a study using different alloys of stainless steel in the fuel cell. He found that the most energy
efficient cell contained a thin sheet of a high density steel alloy (Davies, et al., 2000, 240). His work concluded that while
stainless steel materials were vulnerable to corrosion, the limitation was outweighed by its high conductivity and relatively
low cost of manufacture (Davies, et al., 2000, 241). In order to successfully market these fuel cells, the materials used
must also be capable of being mass produced at a relatively low cost. Other research has been conducted using materials such
as carbon composites, which have a lesser occurrence of corrosion but also a decreased conductivity. Once the ideal fuel cell
has been produced, its only limitation will be the amount of fuel it can store. Systems are being devised to created hydrogen
storage units, which could “refill” the fuel cell with hydrogen fuel. With the abundance of hydrogen and the efficiency
of current prototypes, micro fuel cells have an overall longer life than batteries.
New innovations are arising rapidly within the fuel cell industry. The fuel cell was originally developed as a large
scale energy source and specifically, a more efficient power source for transportation. Recent developments in micro technology
have allowed for fuel cells to be created on a smaller, more practical scale for everyday use. The fuel cell industry has
been well-funded by manufacturers with nested interests in energy. Within the last year, researchers at Stanford University
have developed a new arrangement for micro fuel cells that allows for more flexibility in size and shape (Lee, 2002, 410).
In the past, micro fuel cells have been connected in a vertical stack. This particular arrangement was found to be bulky,
inefficient, and inflexible (Lee, 2002, 412). S.J. Lee and his colleagues developed a “flip-flop arrangement,”
which is a simple planar arrangement of connected individual cells. This “flip-flop arrangement” allows the cells
to maintain a slim form while still being connected efficiently to maximize energy output. Lee named this configuration a
“flip-flop arrangement” based on the nature of the alternating connections between fuel cells (Lee, 2002, 410).
A single fuel cell has a thickness of about 4-5 mm. Using Lee’s “flip-flop arrangement,” the fuel cells
can be connected while maintaining this thickness. In his results, Lee found that fuel cells operating under his “flip-flop
arrangement” had the same electrical output as conventional vertically-arranged fuel cells (Lee, 2002, 412). This reduced
size and greater flexibility allows for manufacturers to integrate micro fuel cells into their products more easily (Lee,
2002, 416). For example, the “flip-flop arrangement” of fuel cells can easily snap into the battery compartment
of a cellular phone, whereas a vertical stack of cells would be about as wide as the phone itself. Lee’s research opens
new possibilities for micro fuel cell arrangements, which will ultimately help incorporate micro fuel cells into the consumer
economy.
Based on the research of individuals such as D.P. Davies and S.J. Lee, micro fuel cells may soon become a part of our
everyday lives. All signs seem to indicate that the technology is available to mass produce micro fuel cells. Certain limitations
still exist, however, most notably issues with the manufacture of materials and the source of fuel. Nevertheless, at the rate
of current research, the question seems to be no longer “How?” but “When?”
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