Personal digital assistant , fuel

Fuel cells can be used to power a variety of portable devices, from handheld electronics such as cell phones and radios to larger equipment such as portable generators. Other potential applications include laptop computers, personal digital assistants (PDAs), and handheld video cameras—almost any application that has traditionally used batteries. These fuel cells have the potential to last more than three times as long as batteries between refueling. 

Figure 6.12 Developmental miniature methanol fuel cells for electronic applications (a) Toshiba, for digital audio players and wireless headsets for mobile phones (b) NEC, for mobile phones (c) Hitachi, for personal digital assistants (d) Motorola, with methanol capsules, for mobile phones (e) Casio, for laptop computers.

The explosive growth of semiconductor industry has been fueled by the relentless pursuit for miniaturization of semiconductor devices. The minimal feature sizes or critical dimensions (CDs) of semiconductor devices in mass production have shrunk from 10p,m more than 30 years ago to less than 100 nm in 2005. According to the International Technology Roadmap for Semiconductors, this miniaturization trend is expected to continue unabated with the production of sub-25 nm generations of devices later next decade [1]. The miniaturization of semiconductor devices has made it possible to offer a host of sophisticated devices and equipment, from super computers, personal computers, personal digital assistants, cellular phones to medical devices and household appliances, with ever increasing performance at steadily reduced prices per transistor or bit. 

A micro fuel cell is a compact miniaturized fuel cell with sizes ranging from a few square millimeters to 1000 mm. They are used as a portable power source for cell phones, laptop computers, personal digital assistants, and other portable low-power electronic devices. The power densities of miniature FCs range from a few tens of microwatts per square centimeter up to several hundreds of milliwatts per square centimeter. Miniature fuel cells... 

The first commercial application for high volume MEA production will be for small portable electronics, which is driven by ever increasing power requirements and for longer duration energy sources. The US Fuel Cell Council, which has over 115 corporate members, has forecasted that the fuel cell market for small portable electronics will be 2 billion by 2011 with the potential of a 70% market penetration into the lithium ion battery market by 2007. To get a better understanding of this market size it is also forecasted that there will be 1.6 billion cell phone subscribers in 2007 worldwide, 76 million laptop shipments in 2007 and 37 million shipments of PDAs (personal digital assistants) in 2007. 

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