Eat your heart out Ant-man! A team of researchers at Massachusetts Institute of Technology have put the diminutive Marvel hero’s shrinking technology to shame with a method of shrinking that allows the construction of complex 3D shapes at the nanoscale. The technology will also allow the manipulation of materials like quantum dots, metals and even DNA.

Edward Boyden, senior author of the paper, published in December’s edition of Science and an associate professor of Biological Engineering and of Brain and Cognitive Sciences at MIT said: “It’s a way of putting nearly any kind of material into a 3-D pattern with nanoscale precision.”

The newly developed technique allows researchers to create any shape or structure they desire by shaping a polymer scaffold with a laser. Various materials can then be attached to this scaffold and it can be shrunk down a thousandth of its initial volume.

Clearly, there is almost no limit to the possible applications of such a system; from robotics, quantum computing, surgery and medicine. What’s more is as it uses materials commonly available in must University labs, it may be widely accessible very shortly for researchers wanting to give it a try.

Why is this so revolutionary?

3D nanostructures created by implosion Fabrication (MIT)

Creation of nanostructures is nothing new, but what makes this latest breakthrough so exciting is the fact that, up until now, 3D patterns have been difficult to build at such scales. They can be made by gradually building structures layer by layer, but the process is slow and extremely challenging.

Methods of 3D nanostructure production have also been limited to the production of self-supporting structures and the use of materials like polymers and plastics, severely limiting the possible applications of such products.

To get around these limitations Boydon and his team used a method developed in their lab to examine brain tissues, expansion microscopy, which involves embedding tissue into a hydrogel and then expanding it, allowing for high-resolution imaging with a regular microscope.

They essentially reversed this process, placing structures in the hydrogel and shrinking them to nanoscale, a method they have termed as Implosion Fabrication.

Implosion Fabrication: how it works

The team used an extremely absorbent material known as polyacrylate, which is commonly found in diapers and nappies, as the scaffold for their nanofabrication process. This scaffold was then bathed in a solution that contains molecules of fluorescein, which attach to it when activated by laser light.

Boydon believes that labs are already stocked with the materials to begin implosion fabrication (MIT)

Fluorescein molecules were then attached to specific locations within the gel using two-photon microscopy, points at which other materials and molecules can be attached which they refer to as anchors.

Boyden explains: “You attach the anchors where you want with light, and later you can attach whatever you want to the anchors.

“It could be a quantum dot, it could be a piece of DNA, it could be a gold nanoparticle.”

Daniel Oran, co-author and graduate student adds: “It’s a bit like film photography — a latent image is formed by exposing a sensitive material in a gel to light. Then, you can develop that latent image into a real image by attaching another material, silver, afterwards.

“In this way, implosion fabrication can create all sorts of structures, including gradients, unconnected structures, and multimaterial patterns.”

Once the required materials are added in the specifically chosen locations, acid is applied which blocks negative charges in the polyacrylate gel so that they no longer repel each other, causing the gel to contract.

Using this technique, the researchers can shrink the objects 10-fold in each dimension (a 1,000-fold reduction in volume). This ability to shrink not only allows for increased resolution, but also makes it possible to assemble materials in a low-density scaffold. This enables easy access for modification, and later the material becomes a dense solid when it is shrunk.

Patterned Alice in Wonderland Implosion Fabrication demonstration (MIT)

Currently, the researchers can create objects that are around 1 cubic millimetre, patterned with a resolution of 50 nanometers. There is a tradeoff between size and resolution: If the researchers want to make larger objects, about 1 cubic centimetre, they can achieve a resolution of about 500 nanometers. However, that resolution could be improved with further refinement of the process, the researchers say.

Future applications of Implosion Fabrication

If all this seems very removed from everyday life it’s worth considering that one of the first applications of this method is likely to be in the creation of smaller lenses.

This could spark a technological revolution for devices such as cameras, telescopes and mobile phones. It could also revolutionise medical technology by allowing the creation of extremely small endoscopes and other internal cameras making such investigations less daunting and much less invasive.

“There are all kinds of things you can do with this,” Boyden says. “Democratizing nanofabrication could open up frontiers we can’t yet imagine.”

Original Research: http://science.sciencemag.org/content/362/6420/1281