A new 3D nanofabrication technique called Implosion Fabrication could be used to create a wide variety of nano- and microstructures not previously possible. The technique, which can print 3D objects of nearly any shape by patterning a polymer scaffold with a laser and then shrinking the structure to a thousandth of its original volume, might be used to make novel optical metamaterials and electronics devices.

Most existing nanofabrication techniques are limited in what they can produce. Direct laser writing methods, for example, can produce 2D patterns but not 3D ones, which need to be built up a layer at a time – a process that is difficult and slow. Lithography, one of the oldest nanofabrication techniques, can again only print 2D layers on patterned surfaces.

Researchers led by Edward Boyden of the Massachusetts Institute of Technology have now put forward a new technique in which they use a laser to create patterns of reactive chemical groups inside a hydrogel scaffold. They then deposit material (which can be anything from quantum dots, a piece of DNA or gold nanoparticles) into the reactive groups in 3D. Finally, they dehydrate the gel (using an acid), which implodes the scaffold and the printed object it contains to a thousandth its original volume and form a nanoscale structure.

The researchers showed that their ImpFab technique works by printing highly conducting 3D nanostructures in silver that keep their complex array shape after shrinkage.

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