Manufacturing complex 3D metallic structures at nanoscale made possible

October 19, 2012

The fabrication of many objects, machines, and devices around us rely on the controlled deformation of metals by industrial processes such as bending, shearing, and stamping. Is this technology transferrable to nanoscale? Can we build similarly complex devices and machines with very small dimensions?

Scientists from Aalto University in Finland and the University of Washington in the US have just demonstrated this to be possible. By combining ion processing and nanolithography they have managed to create complex three-dimensional structures at nanoscale.

The discovery follows from a quest for understanding the irregular folding of metallic thin films after being processed by reactive ion etching.

"We were puzzled by the strong-width-dependent curvatures in the metallic strips. Usually initially-strained bilayer metals do not curl up this way," explains Khattiya Chalapat from Aalto University.

This video is not supported by your browser at this time.

The puzzle began to unravel when Chalapat noticed, together with Dr. Hua Jiang, that the Ti peak was absent from the EDX spectra of folded Ti/Al bilayers.

Further experiments at the O.V. Lounasmaa Laboratory confirmed that the strips bend upward with strong width-dependent curvatures if the bottom layer of the strips is made more reactive to than the top surface.

In nature, similar geometrical effects take place in self-organization directly observable to the . When dandelion flowers bloom, one may try cutting the flower stem into small strips; put them in water, and the strips will fold with observable width-dependent curvatures due to differences in the between the inside and outside parts of the stem.

"Our idea was to find a way to adapt these natural processes to nanofabrication. This led us to an incidental finding that a focused can locally induce bending with nanoscale resolution."

The technology has various applications in the fabrication of . The structures are surprisingly resilient:­ the team found them to be quite sturdy and robust under a variety of adverse conditions, such as electrostatic discharge and heating.

"Because the structures are so small, the coupling and the magnitude of typical nanoscale forces acting on them would be commensurately small," reminds Docent Sorin Paraoanu, the leader of the Kvantti research group, Aalto University.

"As for applications, we have demonstrated so far that these structures can capture and retain particles with dimensions of the order of a micrometer. However, we believe that we are just scratching the tip of the iceberg: a comprehensive theory of ion-assisted self-assembly processes is yet to be reached," notes Paraoanu.

The research has been recently published in the Early View edition of Advanced Materials.

Explore further: Knowing when to fold: Engineers use 'nano-origami' to build tiny electronic devices (Video)

More information: onlinelibrary.wiley.com/doi/10.1002/adma.201202549/abstract

Related Stories

Carving at the nanoscale

December 8, 2011

Researchers at the Catalan Institute of Nanotechnology have successfully demonstrated a new method for producing a wide variety of complex hollow nanoparticles. The work, published this week in Science, applies well known ...

Recommended for you

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

Scientists grow high-quality graphene from tea tree extract

August 21, 2015

(Phys.org)—Graphene has been grown from materials as diverse as plastic, cockroaches, Girl Scout cookies, and dog feces, and can theoretically be grown from any carbon source. However, scientists are still looking for a ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.