Robots hold key to "hydrogen economy"

Research at Rensselaer Polytechnic is tackling what may be among the biggest problems, the high cost of producing fuel cells. The project, which combines the resources of Rensselaer's Flexible Manufacturing Center (FMC) and the Center for Automation Technologies and Systems, recently received a major award from the Robotics Industries Association (RIA).

Rensselaer will receive three industrial robots to help it develop a robotic process to produce fuel-cell stacks. "We are addressing a component that represents a major portion of the total system cost, the stack assembly in a proton-exchange membrane (PEM) fuel cell," says Raymond Puffer, codirector of the FMC.

In PEM fuel cells, hydrogen splits into protons and electrons on one side of a thin polymer membrane. The membrane lets protons pass through, but electrons are forced to go around, creating a flow of electrical current. On the other side of the membrane, electrons recombine with protons and oxygen from the air, creating water and heat as the only byproducts. To produce enough energy for most applications, multiple fuel cells are combined in a fuel-cell stack.

Currently, it can take as long as a full day to assemble and leak-test a single stack. But to be commercially viable, stack assembly must take place in minutes. Researchers plan to create a flexible robotic work cell to handle the materials with great precision. In addition to the three industrial robots donated by the Kuka Robot Group, the RIA award includes collision-avoidance sensors provided by RAD, Tipp City, Ohio, a roboticsaccessories supplier.

"Many of the materials in PEM stacks are thin, flexible, and soaked in corrosive acids, or highly sensitive to changes in humidity and temperature," says Puffer. "This makes material handling orders of magnitude more difficult than methods used for simple flexible materials such as paper."