Thanks to nanotechnology, medical research is moving quickly towards a future where intelligent medical implants can continuously monitor their condition inside the body and autonomously respond to changes such as infection by releasing anti-inflammatory agents. A recent review discusses present and prospective implantable sensors incorporating nanostructured carbon allotropes. The authors describe various applications with an in-depth look at the implantable sensors from the viewpoints of nanomedicine, materials science, nanobiotechnology, and sensor design, both present and future.
Conventional carbon-fiber electrodes have been the material of choice for identifying the chemical nature of neurotransmitters in the brain. Unfortunately, they have some limitations that leave some of the molecules that researchers are interested in just out of our reach. Further miniaturization of biologically compatible, carbon based electrode materials to the nanoscale promises to enhance the very characteristics that made microelectrodes so transformative in the first place, enabling high speed measurements in discrete spatial locations.
In new work, researchers have demonstrated that flexible cotton threads can be used as a platform to fabricate a cable-type supercapacitor. Wearable electronics will go far beyond just very small electronic devices or wearable, flexible computers. Not only will these devices be embedded in textile substrates but an electronics device or system could ultimately become the fabric itself. Supercapacitors with a cable-type architecture could lead to flexible energy storage devices that can remove traditional restriction and achieve a subversive technology that could open up a path for design innovation.
Using quantum dots as the basis for solar cells is not a new idea, but attempts to make such devices have not yet achieved sufficiently high efficiency in converting sunlight to power. Although these performance levels are promising, all high-performing device results to date have relied on a multiple-layer-by-layer strategy for film fabrication rather than employing a single-layer deposition process. Now, though, researchers have developed a semiconductor ink with the goal of enabling the coating of large areas of solar cell substrates in a single deposition step and thereby eliminating tens of deposition steps necessary with the previous layer-by-layer method.
In contrast to flexible electronics, which rely on bendable substrates, truly foldable electronics require a foldable substrate with a very stable conductor that can withstand folding, i.e. an edge in the substrate at the point of the fold, which develops creases, and the deformation remains even after unfolding. That means that, in addition to a foldable substrate like paper, the conductor that is deposited on this substrate also needs to be foldable. Researchers have now demonstrated a fabrication process for foldable graphene circuits based on paper substrates.
Graphene has a unique combination of properties that is ideal for next-generation electronics, including mechanical flexibility, high electrical conductivity, and chemical stability. Combine this with inkjet printing, already extensively demonstrated with conductive metal nanoparticle ink, and you get an inexpensive and scalable path for exploiting these properties in real-world technologies. Although liquid-phase graphene dispersions have been demonstrated, researchers are still struggling with sophisticated inkjet printing technologies that allow efficient and reliable mass production of high-quality graphene patterns for practical applications. Recent work has addressed these issues and proposes an approach to overcome these problems.
Vault particles are large, barrel-shaped nanoparticles found in the cytoplasm of all mammalian cells. All human cells so far analyzed have been shown to contain vaults with quantities varying from a few thousand per cell to in excess of 100 000 per cell. As naturally occurring nanoscale capsules, vaults may be useful to engineer as therapeutic delivery vehicles. The particles can be produced in large quantities and are assembled in situ from multiple copies of the single structural protein following expression. Using molecular engineering, recombinant vaults can be functionally modified and targeted, and their contents can be controlled by packaging.
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.