ducation and outreach." The ability to make tiny things vibrate at very high frequencies offers many potential applications in electronics. From guitar strings on down, the fre- quency at which an object vibrates depends on its mass and dimensions. Nanoscale objects can be made to vibrate at radio frequencies (up to hundreds of megahertz) and SO can substitute for other components in electronic cir- cuits. Cell phones and other wireless devices, for example, usually use the oscil- lations of a quartz crystal to generate the carrier wave on which they transmit or to tune in an incoming signal. A tiny vibrating nanorod might do the same job in vastly less space, while drawing only milliwatts of power. Research by the Cornell NEMS group has shown that these oscillations can be tuned to a very narrow range of frequencies-a property referred to in elec- tronics as "high Q"-which makes them useful as filters to separate signals of different frequencies. They also may be used to detect vibrations to help locate STORAGE objects or detect faint sounds that could predict the failure of machinery or structures. As the nanoguitar shows, NEMS can be used to modulate light, meaning they might be used in fiber-optic communications systems. Such systems currently require a laser at each end for two-way communication. Instead, Craighead suggests that a powerful laser at one end could send a beam that would be modulated and reflected back by a far less expensive NEMS device. This could make it more economical to run fiber-optic connections to private homes or to desktop computers in an office. 2.14 STORAGE As mobile devices become more capable, they'll need to store a growing amount of data. Getting tiny mobile units to store vast quantities of informa- tion isn't easy, however, given physical space restraints. But researchers are working hard to pack data into ever-smaller amounts of space. 2.14.1 Tiny Hard Drive Toshiba has developed a 0.85-inch hard disk drive, the first hard drive to deliver multi-gigabyte data storage to a su