A team of researchers from NIMS and the University of Connecticut has developed a printing technique capable of forming a periodic nano/microstructure on the surface of a polydimethylsiloxane (PDMS) slab and easily transferring it onto the surface of a glass substrate. This technique enables us to create materials with useful functions — including water-repellency and the ability to generate structural colors — without expensive equipment and complex processes. In addition, the technique may be used to fabricate materials capable of realizing anti-fogging and/or generating structural colors on their surfaces — functions potentially useful in the development of innovative gas sensors.
Due to their diverse functional capabilities, periodic nano/microstructures have long been a focus of research and development in materials science. Fabricating them using conventional techniques is, however, a lengthy process requiring the use of large, expensive equipment. In addition, these techniques are unsuitable for creating periodic nano/microstructures over large surface areas. Although this could be achieved using existing printing technologies, inks suitable for forming periodic nano/microstructures and methods of refilling them are still being explored. A simple technique for fabricating periodic nano/microstructures was therefore highly demanded.
This research team recently developed an easy, repeatable technique for printing a periodic nano/microstructure on a glass substrate surface using a PDMS slab. A PDMS slab contains liquid PDMS which functions as an ink when it is exuded from the slab’s surface. The slab is able to form a periodic wrinkled structure on its surface. This can then be transferred to a glass surface by bringing the PDMS slab into contact with the glass surface and then removing it, leaving the periodic nano/microstructure behind. Other types of periodic nano/microstructures can be printed on the surface of a glass substrate in addition to winkle structure, such as columnar and wavy structures. Moreover, other substances (e.g., silicone oils and silica nanoparticles) can be dispersed in liquid PDMS, allowing the resulting periodic nano/microstructures to have properties desirable for a variety of intended purposes.
Using this newly developed printing technique, the team hopes to create periodic nano/microstructures that can be used to satisfy social demands by realizing anti-fogging or generating structural colors on their surfaces — functions potentially useful in the development of innovative gas sensors. The technique could also be used to fabricate superhydrophobic and superoleophobic surfaces and materials useful in atmospheric water harvesting. To achieve these goals, the team first plans to optimize the experimental conditions under which it can produce various forms of printable periodic nano/microstructures.