| Environment News Service
10:15 a.m. May. 1, 2000 PDT
CLEVELAND, Ohio -- A miniature fuel cell with a volume of only five cubic millimeters -- the size of a pencil eraser -- has been developed by researchers at Case Western Reserve University. The new fuel cell was produced using high-tech mini-fabrication techniques.
"The rash of new electronic products on the market over the last dozen years and the rush to further miniaturize these devices has driven the demand for this technology," said Robert Savinell, director of the Ernest B. Yeager Center for Electrochemical Science and associate dean of the Case School of Engineering. Savinell said for the commercial market, the new miniature fuel cells could be used in everything from automobiles to cellphones and computers. "The major portion of the weight and volume of a portable computer or cell phone is the battery system. The size of the power pack is a major limitation for portable electronic devices," he said.
Fuel cells directly convert the chemical energy in a fuel, such as hydrogen or methanol, into electricity. The power generation produces no emissions except water vapor. The fuel cells can deliver more energy per volume and weight than batteries, even when including the volume and weight of the stored fuel.
Savinell is working with co-researchers C.C. Liu, the Walter R. Persons Professor of Sensor Technology at the Case School of Engineering; Morton Litt, professor of macromolecular science at the Case School of Engineering; Jesse Wainright, a principal researcher; and Lauri Dudeck, an engineer.
The team uses minifabrication technology to print multiple layers of fuel cell components onto a substrate that will permit low cost, high volume production of fuel cells rather than building them by hand.
The goal is to produce fuel cells the way that integrated circuits are now manufactured.
"The concepts used in semiconductor processing make it possible to fabricate thousands or millions of devices as easily and in the same time as it takes to fabricate one component by conventional processes. We have created inks for each of the materials needed to create the fuel cell, and discovered how to screenprint those inks onto a structure to form a functioning device," said Savinell.
"This new miniature fuel cell ripens the conditions to someday create micro-systems -- fuel cells coupled with electronic circuitry, micro processors, sensors, and transmitters on a single silicon chip," he said.
The prototype device uses hydrogen, safely stored in a low pressure hydride, as a fuel.
An advanced version of the fuel cell, which would use methanol as a fuel to provide far greater energy storage capability, is under development.
Savinell's research is funded by $2.2 million in grants and contracts from the Defense Advance Research Projects Agency, an arm of the U.S. Department of Defense. He says the military will most likely see this new micro-system technology first.
"Through technology transfer, the military could conceivably couple our fuel cell with miniature sensors that detect motion or even chemical warfare agents, add a transmitter that sends a signal to a remote receiver, and give a soldier advance warning of any threat," said Savinell.
Cars of the future are likely to operate on fuel cells alone, or with a hybrid system using both batteries and fuel cells in which the battery provides power for acceleration and speed and the fuel cell provides energy for longer distances before refueling.
All of the major automotive manufacturers are now developing fuel cells as replacements for internal combustion engines that emit heat-trapping greenhouse gases such as carbon dioxide.
Copyright Environment News Service (ENS) 2000