Sometimes, if you want something made right, you've just got to make it yourself. That could certainly be the case when using molecules to construct microscopic devices such as medication-delivering nano-robots. It was with such applications in mind that scientists from ETH Zurich and IBM recently developed a process for building custom molecules from mix-n-match components.

The process begins with scientists choosing various microspheres made from a polymer or silica. Each one has a diameter of about one micrometer, plus they can each possess different physical qualities. These are placed side-by-side in tiny indentations, which are engraved in polymer templates. Each sphere is placed individually, allowing its position within the finished structure to be precisely dictated.

Heat is then applied, causing each sphere to bond with its neighbors. The completed artificial molecule is then removed from the template, and can be placed in a solution.

Unlike the case with micro-3D printing, the new technology allows single micro-structures to be made from multiple materials. To date, simple things such as rods, triangles and other basic shapes have been created. Ultimately, it is hoped that the molecules could be used to create not only nano-robots, but also things such as micro-mixers for lab-on-a-chip devices.

"Depending on the perspective, it's possible to speak of giant molecules or micro-objects," says ETH's Prof. Lucio Isa, who led the research along with IBM's Heiko Wolf. "So far, no scientist has succeeded in fully controlling the sequence of individual components when producing artificial molecules on the micro scale."

Until now, that is.

Source: ETH Zurich