Microtweezers developed by researchers at Purdue University (Lafayette, IN) may facilitate the manufacture and assembly of microelectromechanical systems (MEMS). Capable of manipulating tiny structures, the microtweezers could contribute to the development of advanced sensors and may someday be suitable for working with live stem cell spheres in research settings as well.

Purdue microtweezers can be used to assemble tiny polystyrene spheres, each with a diameter of 40 micrometers, at left, into 3-D shapes. The device also might be used to weigh tiny particles by placing them onto the tip of a structure called a microcantilever, at right. Photo: Birck Nanotechnology Center

Potentially broadening the scope of MEMS devices, the microtweezers allow users to assemble components in a manner comparable to building with Legos, according to Cagri Savran, an associate professor of mechanical engineering at Purdue. "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 says.

Consisting of a standard micrometer, a two-pronged silicon tweezer, and a graphite interface, the tool does not require electrical power sources nor does it feature hinges or components that operate via thermal, magnetic, or electric influences, according to the researchers. Instead, the Purdue researchers' compact, portable microtweezers feature a single, springy compliant structure. As a result, the researchers note, their design is simpler and less expensive to manufacture than other microtweezers.

The new design could allow for precise isolation of individual stem cell spheres and subsequent positioning of the particles, Savran notes. "We currently are working to weigh single microparticles, individually selected among many others, which is important because precise measurements of an object's mass reveal key traits, making it possible to identify composition and other characteristics," he says. "This will now be as easy as selecting and weighing a single melon out of many melons in a supermarket."

In addition, the microtweezers, if commercialized, could be employed in the printing of chemical or protein dots onto microcantilevers. By creating a functionalized surface on these components, the researchers believe that the enhanced microcantilevers could enable development of advanced sensing technologies. Resulting technologies could potentially detect several substances simultaneously and require smaller sample sizes than conventional diagnostic methods.