Top Trends Impacting Design Engineers, part 1

Despite international tensions and economic problems, technology continues to advance. In the pages that follow Machine Design looks at trends likely to pave the way for hot products in the months to come. How long does the battery in your laptop last? If you're like most people, your answer is, not long enough. That's the driving force behind the increasing interest in low-cost, efficient power sources such as better batteries and practical fuel cells. As consumer demand for portable electronic devices continues to ramp up, designers are looking at new ways to power these devices. Lithium-ion batteries have begun to replace nickel-based chemistries such as nickel-cadmium and nickel-metal-hydride in cell phones and notebook computers. The reason: Lithium-ion cells have a low self-discharge rate, a big limitation of nickel-based batteries. Looking past lithium-ion power, Lithium-polymer, or Li-Poly, batteries are poised to take over. Li-Poly uses the same basic chemistry but replaces the liquid electrolyte with a solid polymer. This reduces the physical size of the battery and eliminates the need for a metal casing, lowering cost. Because the polymer can remain stable through the shaping process, it can be formed into odd shapes depending on the application, possibly letting the battery become a part of the device casing itself. Other advantages include the ability to fit in low-profile and flexible-form factors. The gelled electrolyte also weighs relatively little and there's little chance of electrolyte leakage or overcharging. Limitations for the time being include lower energy density and a higher manufacturing cost. But as demand rises, production volumes should increase and drive down costs. Fuel cells, believe it or not, are the other contender for powering the next generation of portable electronics. Though automotive uses have gotten most of the limelight, micro fuel cells now on the drawing board will convert methanol, ethanol,