thetic jet module in prin- ENERGY TO GO-POWER GENERATION ciple resembles a tiny stereo speaker in which a diaphragm is mounted within a cavity that has one or more orifices. Electromagnetic or piezoelectric drivers cause the diaphragm to vibrate 100 to 200 times per second, sucking sur- rounding air into the cavity and then expelling it. The rapid cycling of air into and out of the module creates pulsating jets that can be directed to the precise locations where cooling is needed. The jet cooling modules take up less space in cramped equipment housings and can be flexibly conformed to components that need cooling-even mounted directly within the cooling fins of heat sinks. Arrays of jets would provide cooling matched to component needs, and the devices could even be switched on and off to meet changing thermal demands. Although the jets move 70 percent less air than fans of comparable size, the airflow they produce contains tiny vortices that make the flow turbulent, encouraging efficient mixing with ambient air and breaking up thermal boundary layers. "You get a much higher heat transfer coefficient with synthetic jets, SO you do away with the major cooling bottleneck seen in conventional systems," says Mahalingam. The ability to scale the jet modules to suit specific applications and to integrate them into electronic equipment could provide cooling solu- tions over a broad range of electronic hardware ranging from desktop com- puters to PDAs, mobile phones, and other portable devices that are now too small or have too little power for active cooling. SynJets could be used by themselves to supplement fans or even in con- junction with cooling liquid atomization. "We will fit in where there currently is no solution or improve on an existing solution," says Jonathan Goldman, a commercialization catalyst with Georgia Tech's VentureLab, a program that helps faculty members commercialize the technology they develop. Beyond the diaphragm, the system requires an electronic driver and wiring. Goldman expects the jets to