Diamond-like carbon (DLC) coatings are commonly used in medical implants to greatly improve their resistance to environmental factors. Though impressively strong and impermeable, DLC will often break off from the implants to become a nuisance within the body. Now scientists at Empa, a Swiss research institution, have discovered why that happens and what can be done to prevent the chipping.

“When two materials are placed in contact with each other, the result is a reaction layer at the interface between them, which is only several atomic layers thick. Thus a new material is formed, which we investigated now for the first time”, explains Roland Hauert of Empa’s “Nanoscale Materials Science” laboratory.
His team showed that the so far barely considered reaction layer, which is not always completely corrosion resistant, is responsible for the detachment of the DLC layer. On the one hand, stress corrosion cracking occurred in the reaction layer. The mechanical load in conjunction with the penetration of body fluids led to slow-growing cracks, which in turn caused the DLC substrate to detach little by little.
In other cases, crevice corrosion was responsible for the damage. Over time, an aggressive, acidic medium develops in fine crevices and slowly dissolves the reaction layer or the additional adhesive layer, likewise leading to detachment.
But the Empa team didn’t stop there; together with their industry partners Synthes and Ionbond, they developed a corrosion-resistant intermediate layer at the interface to the DLC layer. What’s more, the researchers also developed a process that can determine a crack’s growth rate under conditions similar to those experienced in the human body as well as the dissolution rate of the reaction layer in cases of crevice corrosion.

Full story from Empa: Nanocorrosion causes implants to fail…

Scientists from Case Western Reserve and Vanderbilt universities are reporting a surprising finding that lasers can be used to pace the contractions of embryonic quail hearts. It has been reported previously that light can excite cardiac tissue, but this is the first time that a heart rate was set to a particular frequency using light.

According to the scientists, this non-invasive device may prove an effective tool in understanding how environmental factors that alter an embryo’s heart rate lead to congenital defects. It may also lead to investigations of cardiac electrophysiology at the cellular, tissue and organ levels, and possibly the development of a new generation of pacemakers.
“The mechanisms behind many congenital defects are not well known. But, there is a suspicion that when the early embryonic heart beats slower or faster than normal, that changes gene regulation and changes development,” said Michael Jenkins, a postdoctoral researcher in biomedical engineering at Case Western Reserve.
Jenkins came up with the idea to try the infrared laser on an embryonic heart. He stumbled on an obscure paper from the 1960s in which researchers found that continuous exposure to visible light accelerated the heart rate of an embryonic chicken. He also knew of the success that Eric D. “Duco” Jansen, a professor of biomedical engineering at Vanderbilt University, had using an infrared laser to stimulate nerves. He then hypothesized that pulsed infrared light may enable pacing of the embryonic heart.

Case Western press release: A heart beats to a different drummer…
Article in Nature Photonics: Optical pacing of the embryonic heart

A new discovery, reported in the latest Nature, hints at higher universal laws of the physical world, as well as new ways to approach and understand life in general. Even though the European discovery actually dealt with superconductors, it has an interesting twist with implications for the life sciences.
A group of physicists from London Centre for Nanotechnology at UCL and their collaborators at Sapienza University of Rome and European Synchrotron Radiation Facility in Grenoble, France were studying properties of so-called high-transition-temperature (high-T_c) copper oxide superconductors. They were looking at the microstructures that these superconductors form as they are cooled down. To the surprise of investigators, they discovered that microstructures, exhibited by oxygen atoms, seemed to organize into self-repeating fractals. Moreover, these fractal shapes, some extending almost to the millimeter scale, were correlating to superconductivity. In fact, larger fractals correlated with higher superconductivity temps.
What does it have to do with life? We think, plenty. Fractals, known for their geometric morphologies that are made up of patterns that repeat themselves at smaller scales infinitely, were first discovered by mathematician Benoit Mandelbrot in 1960s. Since then, they took the world of natural sciences by storm. As mathematicians and physicists discovered more and more interesting properties of these unique constructs, people started to notice fractals’ ubiquitous presence in nature. Whether in the living world or in inorganic one, they seem to pop up in unexpected places. Somehow, there are laws of physics that favor these structures for whatever reason.
To us, the discovery of fractal function is eerily reminiscent of polarization in pre-quantum mechanical physics. Not until Niels Bohr, Albert Einstein and others laid the foundations of quantum mechanics, polarization of light has remained a mystery. Now we have a new puzzle to answer. Fractals are ubiquitous in the physical and living world for some unknown reason, and there is a function to them.
Paper in Nature: Scale-free structural organization of oxygen interstitials in La₂CuO_4+y
UCL press release: Fractals make better superconductors …
More from Wired: Inexplicable Superconductor Fractals Hint at Higher Universal Laws…
Side image: Heat treatment improves the superconductivity of a ceramic copper oxide by creating a fractal network of connected channels of ordered oxygen defects. The green and red spheres represent the paired electrons responsible for superconductivity. Artwork by Manuel Vogtli (LCN).

The UK supermarket chain Sainsbury’s is running a trial with two different drug vending machines in two of its West Sussex stores. Basically you can drop your prescription at the machine, the pharmacy will collect the prescriptions and deliver the medications which you can later pick up. As the machines are placed in stores with an in-store pharmacy service, the only benefit seems to be the lack of face-to-face contact (for those people who consider that a benefit). The trial will run for a year after which it will be decided whether they will be rolled-out across all of England.
Some UK hospitals plan to trial a more useful drug vending machines this winter, which have a video-link and can dispense medication directly. Patient and pharmacists can talk to each other and a photograph of the prescription is sent over at the same time. The pharmacist can then authorize the machine to deliver drugs from an internal stock. This might prove a useful application for remote places and to provide coverage during evenings, nights and weekends. Although law currently only permits use of these machines in hospitals and healthcare centers, PharmaTrust, the company supplying the machines, hopes that in the future they will be able to place them in High Streets, shopping malls and rural locations.

Source: BBC News…

Just a decade after HAL 9000 was supposed to make its appearance, researchers at the University of Hertfordshire have unveiled a prototype of a robot capable of developing emotions through interactions with human caregivers and getting emotionally attached to them. The robots are programmed to learn to interact with humans the same way babies do, using the same expressive and behavioral cues. This has been implemented by modeling early attachment processes in human and chimpanzee infants. They will become attached to their primary caregiver, developing a stronger bond as they interact. They can express anger, fear, sadness, happiness, excitement and pride, or show distress if not cared for in stressful situations. Still to be added is understanding of non-verbal cues and emotions expressed through physical postures, gestures and body movements. The robots have been developed as part of a project of several universities and robotics companies funded by the European Commission called FEELIX GROWING (Feel, Interact, eXpress: a Global approach to development with Interdisciplinary Grounding). One of the future goals is to have the robot be a carer/companion for diabetic children in the hospital. Here’s a video of an earlier prototype:

Press release: Robots That Develop Emotions in Interaction with Humans…

In two papers presented at the meeting of the Society of Experimental Mechanics in Indianapolis and at the Nanotech 2010 Conference and Expo in Anaheim, California, Purdue University scientists detail a new mechanism that allows for precise automatic calibration of micro electromechanical systems (MEMS). Current methods of calibration are about 10% off the correct number in small scale systems, but the new technique promises near perfect readings leading to precise micro-sensors.

MEMS accelerometers and gyroscopes currently are being used in commercial products, including the Nintendo Wii video game, the iPhone, walking robots and automotive airbags.
“Those MEMS work well because they don’t need ultra-high precision or accuracy,” Clark said. “It is difficult for conventional technology to accurately measure very small forces, such as van der Waals forces between molecules or a phenomenon called the Casimir effect that is due to particles popping in and out of existence everywhere in the universe.”
These forces are measured in “piconewtons,” a trillionth of the weight of a medium-size apple.
“If we are trying to investigate or exploit picoscale phenomena like Casimir forces, van der Waals forces, the hydrogen bond forces in DNA, high-density data storage or even nanoassembly, we need much higher precision and accuracy than conventional methods provide,” Clark said. “With conventional tools, we know we are sensing something, but without accurate measurements it is difficult to fully understand the phenomena, repeat the experiments and create predictive models.”

Press release: Innovation could bring super-accurate sensors, crime forensics