WEST LAFAYETTE, Ind. - Researchers have created new "microtweezers" capable of manipulating objects to build tiny structures, print coatings to make advanced sensors, and grab and position live stem cell spheres for research.
The microtweezers might be used to assemble structures in microelectromechanical systems, or MEMS, which contain tiny moving parts. MEMS accelerometers and gyroscopes currently are being used in commercial products. A wider variety of MEMS devices, however, could be produced through a manufacturing technology that assembles components like microscopic Lego pieces moved individually into place with microtweezers, said Cagri Savran (pronounced Chary Savran), an associate professor of mechanical engineering at Purdue University.
"We've shown how this might be accomplished easily, using new compact and user-friendly microtweezers to assemble polystyrene spheres into three-dimensional shapes," he said.
Research findings were detailed in a paper that appeared online in December in the Journal of Microelectromechanical Systems, or JMEMS. The paper was written by Savran, mechanical engineering graduate students Bin-Da Chan and Farrukh Mateen, electrical and computer engineering graduate student Chun-Li Chang, and biomedical engineering doctoral student Kutay Icoz.
The new tool contains three main parts: a thimble knob from a standard micrometer, a two-pronged tweezer made from silicon, and a "graphite interface," which converts the turning motion of the thimble knob into a pulling-and-pushing action to open and close the tweezer prongs. No electrical power sources are needed, increasing the potential for practical applications. Other types of microtweezers have been developed and are being used in research. However, the new design is simpler both to manufacture and operate, Savran said.
Generally, microcantilevers are functionalized to detect one type of substance by exposing them to fluids, Savran said. However, being able to microprint a sequence of precisely placed dots of different chemicals on each cantilever could make it possible to functionalize a device to detect several substances at once. Such a sensing technology also would require a smaller sample size than conventional diagnostic technologies, making it especially practical.
The new microtweezers are designed to be attached easily to "translation stages" currently used in research. These stages are essentially platforms on which to mount specimens for viewing and manipulating. Unlike most other microtweezers, the new device is highly compact and portable and can be easily detached from a platform and brought to another lab while still holding a micro-size object for study, Savran said.
The two-pronged tweezer is micromachined in a laboratory called a "clean room" with the same techniques used to create microcircuits and computer chips. The research was based at the Birck Nanotechnology Center in Purdue's Discovery Park.
Purdue has filed for a provisional patent on the design.
Writer: Emil Venere, 765-494-4709, firstname.lastname@example.org, Source: Cagri A. Savran, 765 494-8601, email@example.com