Friday, July 9, 2010

This week in nanotechnology - July 9, 2010

Clusters of heated, magnetic nanoparticles targeted to cell membranes can remotely control ion channels, neurons and even animal behavior. The UB researchers demonstrated that their method could open calcium ion channels, activate neurons in cell culture and even manipulate the movements of the tiny nematode, C. elegans.

While those wonderful light sabers in the Star Wars films remain the figment of George Lucas' fertile imagination, light mills – rotary motors driven by light – that can power objects thousands of times greater in size are now fact. Researchers have created the first nano-sized light mill motor whose rotational speed and direction can be controlled by tuning the frequency of the incident light waves.

Researchers have demonstrated how they can adjust process conditions to influence the properties of novel plasma polymer coatings containing silver nanoparticles. Tailor-made films can be generated through a one-step plasma process. The scientists developed these new coatings, which kill bacteria while having no negative effect on human tissue.

At first, nanoshocks may seem like something to describe the millions of aftershocks of a large earthquake. But physicists are using an ultra-fast laser-based technique they dubbed "nanoshocks" for something entirely different. In fact, the "nanoshocks" have such a small spatial scale that scientists can use them to study shock behavior in tiny samples such as thin films or other systems with microscopic dimensions (a few tens of micrometers). In particular they have used the technique to shock materials under high static pressure in a diamond anvil cell.

Researchers are using nanotechnology to develop a medical dressing which will detect and treat infection in wounds. The dressing will work by releasing antibiotics from nanocapsules triggered by the presence of disease-causing pathogenic bacteria, which will target treatment before the infection takes hold. The dressing will also change colour when the antibiotic is released, alerting healthcare professionals that there is infection in the wound.

The tunable fluorescent nanoparticles known as quantum dots make ideal tools for distinguishing and identifying rare cancer cells in tissue biopsies. New research describes how multicolor quantum dots linked to antibodies can distinguish the Reed-Sternberg cells that are characteristic of Hodgkin's lymphoma.

Reed-Sternberg cells

Reed-Sternberg cells can be distinguished by their red outline, blue and white internal staining, and their lack of green staining

Metallic carbon nanotubes show great promise for applications from microelectronics to power lines because of their ballistic transmission of electrons. But who knew magnets could stop those electrons in their tracks? Researchers came to the unexpected conclusion that magnetic fields can turn highly conductive nanotubes into semiconductors.

Biomechanical energy is one of the main energy components in biological systems. Developing an effective technique that can convert biomechanical energy into electricity is important for the future of in vivo implantable biosensors and other nanomedical devices. Researchers have already shown the conversion of biomechanical energy into electricity by a muscle-movement-driven nanogenerator to harvest mechanical energy from body movement under in vitro conditions. In a first demonstration of using nanotechnology to convert tiny physical motion into electricity in an in vivo environment, the same team has now reported the implanting of a nanogenerator in a live rat to harvest energy generated by its breath and heartbeat.