Paper has emerged as a focus area for researchers developing innovative techniques for printed basic electronics components. Another area where paper could lead to low-cost innovative devices and applications is lab-on-a-chip technology. Currently, these microfluidic devices are fairly expensive due to their lithography-based fabrication process with channels patterned in glass or plastic and tiny pumps and valves directing the flow of fluids. Inexpensive paper-based sensing kits already play an important role in ready-to-use diagnostics. Researchers have even managed to create inexpensive microfluidic platforms on hydrophobic paper with laser treatments. In a further advance, scientists have now fabricated a paper-based metamaterial device which can be potentially utilized for quantitative analysis in biochemical sensing applications.
Fabrication of a single nanodevice is no longer the state of the art in nanotechnology. The leading edge - and also currently the most challenging area in nanotechnology - is research that leads to a self-powered nanoscale system that is driven by the energy harvested from its environment and that can perform its work independently and sustainable. This is a key step toward self-powered nanotechnology, which is vitally important for medical science, environmental monitoring, defence technology and even personal electronics. A research team has now provided the first demonstration that a nanogenerator can be strong enough to power a device with the capability of sensing, data processing and wireless data transmission. This is a powerful demonstration of the self-powered nanosystem and its potential applications.
Groundbreaking research has shown a quantum atom has been tracked inside a living human cell and may lead to improvements in the testing and development of new drugs. Researchers conducted studies that confirm that non-invasive quantum measurement is possible on nanodiamonds containing a single nitrogen-vacancy (NV) spin moving within living cells. Studying the quantum properties of a single NV defect within a diamond nanocrystal, the researchers demonstrate a new technique which enables the orientation of a nanoparticle to be determined to an accuracy of less than one degree in an acquisition time of 89 milliseconds. This new technique offers biologists an extra degree of freedom when studying the translational motion of nanoparticles. Monitoring the coherence from a single electron spin paves the ways for nanoscale bio-magnetometry allowing scientists to probe changes in the cell's electromagnetic environment.
Printed electronics is one of the most important new enabling technologies. It will have a major impact on most business activities from publishing and security printing to healthcare, automotive, military and consumer packaged goods sectors. With recent advances, power and energy storage can be integrated into the printing process, making their potential applications even more ubiquitous. Currently, though, the more complex printed components that require a combination of different class of devices, still experience drawbacks in performance, cost, and large-scale manufacturability. Researchers have now succeeded in fabricating a multi-component sensor array by simple printing techniques - all components (polymer sensor array, organic transistors, electrochromic display) are integrated on the same flexible substrate.
Many strategies to develop stretchable electronics rely on engineering new constructs from existing materials, e.g. ultrathin, stretchable silicon structures. Another approach is to fabricate ultrathin CMOS circuits on stretchable materials such as polymers. Nanotechnology allows a novel route to materials and structures that can be used to develop human-friendly devices with realistic functions and abilities that would not be feasible by mere extension of conventional technology. New research suggests devices that can act as part of human skin or clothing, and can therefore be used ubiquitously. Such devices could eventually find a wide range of applications in recreation, virtual reality, robotics and health care.
The complex processes inside living systems emerge from the interactions of countless molecules. Understanding these interactions at the single molecule level is of great importance because mechanisms governing their function can be revealed best by interrogating individual molecules. Scientists rely on single-molecule techniques that allow them to isolate individual molecules and sequentially transport them for measurement and, potentially, manipulation. Most commonly, molecules are interfaced with tools like optical tweezers and atomic force microscopes. These devices are precision force sensors. Many interactions among biological molecules are short lived. Their lifetimes can be as short as a nanosecond. The existing single molecule techniques are limited in their temporal resolution, probing the timescales on the order of several milliseconds to a second. In new work, researchers have extended the reach of single molecule experiments to the microsecond timescale.
In order to get a true picture of the processes and events that take place inside unmodified, living cells, probing techniques need to be non-destructive, noninvasive and in real-time. Due to their small dimensions, high-aspect ratio nanomaterials such as nanofibers, nanowires and carbon nanotubes are ideal for cellular applications since they can cross the cell membrane without causing significant damage. In particular, semiconductor nanowires attract a lot of interest because of their uniformity, reproducibility and possibility of fine-tuning their intrinsic properties - physical dimensions, crystal structure, electrical and optical properties, etc. Researchers have now shown, for the first time, the spontaneous and close interface of arrays of vertically aligned indium arsenide nanowires with two relevant cell lines, human embryonic kidney cells and rat embryonic dorsal root ganglion neurons.
Currently, the most common methods for sizing nanoparticles extract data from bulk measurements. These techniques are inherently averaging and so are unable to effectively resolve mixtures of different-sized particles. While individual nanoparticles can be sized using electron microscopy, this approach is time-consuming and of little utility in assembling significant population statistics. Researchers have now developed a microfluidic device for the all-electronic analysis of complex suspensions of nanoparticles in fluid. This device is capable of detecting and sizing individual and unlabeled particles as small as a few tens of nanometers in diameter at rates estimated to exceed 100,000 particles per second.