Given the vast, and still rising, cost of optical lithography tools, researchers have considered alternative patterning technologies such as electron beam lithography (EBL), and nanoimprint technology (NIL) in order to enable the manufacturing of next-generation integrated circuits, flash memory, and hard disk drives. Now that the length scales attainable by top-down lithography are approaching that of bottom-up self-assembly found in polymers and small molecules, scientists are increasingly looking at bottom-up patterning technologies based on self-assembly.
The past two decades have witnessed the evolution of advanced physical probe-based nanolithography techniques for molecular printing such as for instance Dip-Pen Nanolithography. Now, researchers have demonstrated, for the first time, photo-actuated polymer pens for molecular printing. This represents an important step in the field of scalable nanofabrication. It paves the way for dynamic actuation of individual pens, making it possible to realize patterning and printing molecules or other soft materials such as polymers or biomaterials at high resolution and low cost.
Bagasse, a waste plant matter obtained by food industry processes such as sugarcane processing, has great potential as raw material for the production of cellulose nanofibrils (CNF) for a range of applications. Researchers now have developed a CNF ink from bagasse that has potential as component in bioinks for 3D printing. Bioinks are inks that contain living cells and that can be 3D printed in a cell-friendly manner, without compromising cell viability.
Tuning adhesion without relying on chemical treatment or micro or nanostructured surfaces is now closer with a novel, kirigami-inspired approach. New research shows that by carefully designing arrays of cuts in an adhesive film, the stickiness can not only be tuned by a factor of 100 across a single sheet, but also be decreased for an easy-release purpose. These kirigami-inspired structures at interfaces provide a mechanism to spatially control and enhance adhesion strength while providing directional characteristics for high-capacity, easy-release interfaces.
Cellulose aerogels, made from nanofibrils found in plants, have several unique features, one of which is super high oil absorption capacity that is several times higher than commercial sorbents available in the market. Researchers have created wood-based structures for oil/water separation, utilizing the native feature of wood, i.e. its tubular porosity and hierarchical organization. The novelty here is the development of new processing routes for hierarchical wood structures scaled from nano-, micro-, to macroscales.
Researchers have developed a nanocoating that wipes off dust and sand from a surface by an electrical trigger, e.g. to clean solar panels in desert like conditions. This novel coating forms dynamic surface undulations fuelled by an alternating electric field. This new approach is based on resonance enhanced microscopic (di)electric coupling of polar mesogens to the electric field. Further applications could be removal of water droplets on car screens; dust removal from lenses and other optical systems; and controlling friction at or between surfaces.
Researchers have demonstrated a new paradigm in 3D-printing by using genetically programmed living cells as active components to print living materials and devices. The living cells are engineered to light up in response to a variety of stimuli. When mixed with a slurry of hydrogel and nutrients, the cells can be printed, layer by layer, to form three-dimensional, interactive structures and devices. These printed large-scale high-resolution living materials accurately respond to signaling chemicals in a programmed manners.
Countless commercial and industrial products are routinely produced by manufacturing processes where solid parts are molded through injecting molten polymer into a cast and removing the finished shape once cooled. This process is well understood for solid materials. If the characteristics and properties of a liquid are of interest, e.g., ion transport or mobility, the ability to structure liquids into complex shapes becomes highly desirable. It would open a wide range of potential applications in areas such as all-liquid reaction vessels, energy storage materials, all-liquid electronic devices, and microfluidic devices. Researchers now have developed a very simple route to structure liquids by all-liquid molding.