Purdue Researchers Develop Nanowire-Shaping Process

It's no news that medical implantable devices have undergone steady progress toward miniaturization in the last few years. This process has been aided by breakthroughs in a range of enabling technologies, electronics among them. Now, researchers at Purdue University (West Lafayette, IN) have developed a manufacturing technique for shaping nanowires and ultrathin films that could further the trend toward medical device miniaturization.

Graphene and nanowires have many potential applications, but manufacturing technologies are required to tune them for specific uses. That's where the Purdue researches come in. They are using their method to stamp nano- and microgears, form tiny circular shapes out of graphene, and change the shape of silver nanowires, according to Gary Cheng, associate professor of industrial engineering at Purdue. "We do this shaping at room temperature and atmospheric pressure, like a nano machine shop,"  Cheng explains.

Known as laser shock-induced shaping, the new technique enables the researchers to tune nanowires by altering electrical and optoelectrical properties that are critical for electronic components. The researchers have also shown how laser shock-induced shaping can be used to change the properties of graphene, a step toward harnessing the material for electronic applications. The technique uses a multilayered sandwich structure with a small mold at the bottom. Nanowires are situated directly above the mold, and other materials are layered between the nanowires and a glass cover sheet. Exposing this forming unit to an ultrafast pulsing laser causes one of the layers to burn up, generating downward pressure that forces the nanowires into the mold and changes their shape.

"The process could be scaled up for an industrial roll-to-roll manufacturing process by changing laser beam size and scanning speed," Cheng remarks. "The laser shock-induced shaping approach is fast and low-cost."