Researchers fabricated nanoporous glass films using nanocrystals of cellulose, the main component of pulp and paper. The unique, helical structure of cellulose is replicated in a mineral. This helical organization synthetically mimics the structure of the exoskeletons of some iridescent beetles. Introducing porosity into photonic crystals provides a means to tune their optical properties by infiltrating the pores with various guests: When certain liquids are added to the film, the liquid gets trapped in the pores and changes the optical properties of the films.
For a long time, scientists have been fascinated by the dramatic changes in color used by marine creatures like squids and octopuses, but they never quite understood the mechanism responsible for this. Only recently they found out that a neurotransmitter, acetylcholine, sets in motion a cascade of events that culminate in the addition of phosphate groups to a family of unique proteins called reflectins. Having begun to unravel the natural mechanisms behind these amazing abilities, researchers are trying to use this knowledge to make artificial camouflage coatings. New work addresses the challenge of making something appear and disappear when visualized with standard infrared detection equipment.
Semiconductor fabs are large, complex industrial sites with costs for a single facility approaching $10B. In this article we discuss the possibility of putting the entire functionality of such a fab onto a single silicon chip. We demonstrate a path forward where, for certain applications, especially at the nanometer scale, one might consider using a single chip approach for building devices, both integrated circuits and nano-electromechanical systems. Such methods could mean shorter device development and fabrication times with a significant potential for cost savings.
One of the most restricting parameters in nanofabrication is the difficulty involved with controllably patterning materials at precise locations in a repeatable manner over relatively large areas. A novel microelectromechanical system (MEMS)-based mask writer has now been developed by a team of researchers. The device allows to directly write structures at the nanoscale without the need to use photoresist, lift-off techniques or other complex and expensive approaches. The technique uses a MEMS plate with apertures drilled into it and a shutter so that one can, in effect, spray paint with atoms.
While researchers are working on developing more cost-effective nanolithographic tools such as for instance superlens lithography, one of the key problems with nanofabrication is how to generate ever-challenging patterns with high resolution - especially for 3D nanostructures - and at the same time substantially reduce the cost of the process. A novel nanolithography method is based on light scattering from nanoparticles, which can generate 3D hollow-core structures that resembles 'nano-volcanoes'. Different from traditional lithography methods that are typically based on complex systems, this process relies solely on the light interaction with a single nanoparticle. No masks and external optics are needed in this approach, and light is manipulated into the desired optical pattern solely by the colloids.
Fractals are structures built up from repeated sizings of a simple shape to make a complex one. A fractal is a geometric structure that can repeat itself towards infinity. Zooming in on a fragment of it, the original structure becomes visible again. In biological systems, fractal structures can be found everywhere - bronchial trees, vasculature, and nerve cells. These amazing structures can provide a specific interfacial contact mode that is highly efficient for absorbing sunlight, transporting nutrition, exchanging oxygen and carbon dioxide, and signal transduction. Researchers have now demonstrated the fabrication of programmable fractal gold nanostructured interfaces and their outstanding specific recognition of rare cancer cells from whole blood samples along with their effective release capability.
One major challenge in contemporary science is to accomplish with synthetic building blocks what nature does so well, that is, creating complex and functional structures through multiple levels of assembly of biomolecules. Bottom-up engineering of nanostructures that assemble themselves from polymer molecules are bound to become useful tools in chemistry. To that end, researchers are using block copolymer based micellar architectures to form hierarchical superstructures with defined shape and geometry. Researchers have now demonstrate that nanoparticles tethered with block copolymers resemble micelles that can assemble into well-ordered higher level mesostructures.
Atomically precise manufacturing (APM) can be understood through physics, engineering design principles, proof-of-concept examples, computational modeling, and parallels with familiar technologies. APM is a prospective production technology based on guiding the motion of reactive molecules to build progressively larger components and systems. Bottom-up atomic precision can enable production with unprecedented scope (in terms of product materials, components, systems, and performance), while fundamental mechanical scaling laws can enable unprecedented productivity.