Researchers have learned how to mass produce tiny mechanical devices that could help cell phone users avoid the nuisance of dropped calls and slow downloads. The devices are designed to ease congestion over the airwaves to improve the performance of cell phones and other portable devices.
The overcrowding results in dropped calls, busy signals, degraded call quality and slower downloads. To counter the problem, industry is trying to build systems that operate with more sharply defined channels so that more of them can fit within the available bandwidth.
The Purdue team has created devices called nanoelectromechanical resonators, which contain a tiny beam of silicon that vibrates when voltage is applied. Researchers have shown that the new devices are produced with a nearly 100 percent yield, meaning nearly all of the devices created on silicon wafers were found to function properly.
In addition to their use as future cell phone filters, such nanoresonators also could be used for advanced chemical and biological sensors in medical and homeland-defense applications and possibly as components in computers and electronics.
The devices are created using silicon-on-insulator, or SOI, fabrication - the same method used by industry to manufacture other electronic devices. The resonators can be readily integrated into electronic circuits and systems because SOI is compatible with complementary metal–oxide–semiconductor technology, or CMOS, another mainstay of electronics manufacturing used to manufacture computer chips.
The resonators are in a class of devices called nanoelectromechanical systems, or NEMS.
The new device is said to be "highly tunable," which means it could enable researchers to overcome manufacturing inconsistencies that are common in nanoscale devices.
The heart of the device is a silicon beam attached at two ends. The beam, which vibrates in the center like a jump rope, is about two microns long and 130 nanometers wide, or about 1,000 times thinner than a human hair. Applying alternating current to the beam causes it to selectively vibrate side-to-side or up and down and also allows the beam to be finely adjusted, or tuned.
The nanoresonators were shown to control their vibration frequencies better than other resonators. The devices might replace electronic parts to achieve higher performance and lower power consumption. Not only are they more efficient than their electronic counterparts, but they also are more compact.
The new resonators could provide higher performance than previous MEMS, or microelectromechanical systems.
In sensing application, the design enables researchers to precisely measure the frequency of the vibrating beam, which changes when a particle lands on it. Analyzing this frequency change allows researchers to measure minute masses. Similar sensors are now used to research fundamental scientific questions. However, recent advances may allow for reliable sensing with portable devices, opening up a range of potential applications.
Such sensors have promise in detecting and measuring constituents such as certain proteins or DNA for biological testing in liquids, gases and the air, and the NEMS might find applications in breath analyzers, industrial and food processing, national security and defense, and food and water quality monitoring.
This story is reprinted from material from Purdue University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.